From: Mehdi Amini <joker.eph@gmail.com>
Date: Sat, 15 Aug 2020 07:33:59 +0000 (+0000)
Subject: Revert "Separate the Registration from Loading dialects in the Context"
X-Git-Tag: llvmorg-13-init~14638
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ba92dadf05c50d53e6bc7345f081e0a5f540b01e;p=platform%2Fupstream%2Fllvm.git

Revert "Separate the Registration from Loading dialects in the Context"

This was landed by accident, will reland with the right comments
addressed from the reviews.
Also revert dependent build fixes.
---

diff --git a/flang/unittests/Lower/OpenMPLoweringTest.cpp b/flang/unittests/Lower/OpenMPLoweringTest.cpp
index 4c23845..ad6fe73 100644
--- a/flang/unittests/Lower/OpenMPLoweringTest.cpp
+++ b/flang/unittests/Lower/OpenMPLoweringTest.cpp
@@ -15,7 +15,8 @@
 class OpenMPLoweringTest : public testing::Test {
 protected:
   void SetUp() override {
-    ctx.getOrLoadDialect<mlir::omp::OpenMPDialect>();
+    mlir::registerDialect<mlir::omp::OpenMPDialect>();
+    mlir::registerAllDialects(&ctx);
     mlirOpBuilder.reset(new mlir::OpBuilder(&ctx));
   }
 
diff --git a/mlir/examples/standalone/standalone-opt/standalone-opt.cpp b/mlir/examples/standalone/standalone-opt/standalone-opt.cpp
index eb624b3..5c99058 100644
--- a/mlir/examples/standalone/standalone-opt/standalone-opt.cpp
+++ b/mlir/examples/standalone/standalone-opt/standalone-opt.cpp
@@ -76,7 +76,7 @@ int main(int argc, char **argv) {
   if (showDialects) {
     mlir::MLIRContext context;
     llvm::outs() << "Registered Dialects:\n";
-    for (mlir::Dialect *dialect : context.getLoadedDialects()) {
+    for (mlir::Dialect *dialect : context.getRegisteredDialects()) {
       llvm::outs() << dialect->getNamespace() << "\n";
     }
     return 0;
diff --git a/mlir/examples/toy/Ch2/toyc.cpp b/mlir/examples/toy/Ch2/toyc.cpp
index 99232d8..d0880ce 100644
--- a/mlir/examples/toy/Ch2/toyc.cpp
+++ b/mlir/examples/toy/Ch2/toyc.cpp
@@ -68,9 +68,10 @@ std::unique_ptr<toy::ModuleAST> parseInputFile(llvm::StringRef filename) {
 }
 
 int dumpMLIR() {
-  mlir::MLIRContext context(/*loadAllDialects=*/false);
-  // Load our Dialect in this MLIR Context.
-  context.getOrLoadDialect<mlir::toy::ToyDialect>();
+  // Register our Dialect with MLIR.
+  mlir::registerDialect<mlir::toy::ToyDialect>();
+
+  mlir::MLIRContext context;
 
   // Handle '.toy' input to the compiler.
   if (inputType != InputType::MLIR &&
diff --git a/mlir/examples/toy/Ch3/toyc.cpp b/mlir/examples/toy/Ch3/toyc.cpp
index d0430ce..f9d5631 100644
--- a/mlir/examples/toy/Ch3/toyc.cpp
+++ b/mlir/examples/toy/Ch3/toyc.cpp
@@ -102,10 +102,10 @@ int loadMLIR(llvm::SourceMgr &sourceMgr, mlir::MLIRContext &context,
 }
 
 int dumpMLIR() {
-  mlir::MLIRContext context(/*loadAllDialects=*/false);
-  // Load our Dialect in this MLIR Context.
-  context.getOrLoadDialect<mlir::toy::ToyDialect>();
+  // Register our Dialect with MLIR.
+  mlir::registerDialect<mlir::toy::ToyDialect>();
 
+  mlir::MLIRContext context;
   mlir::OwningModuleRef module;
   llvm::SourceMgr sourceMgr;
   mlir::SourceMgrDiagnosticHandler sourceMgrHandler(sourceMgr, &context);
diff --git a/mlir/examples/toy/Ch4/toyc.cpp b/mlir/examples/toy/Ch4/toyc.cpp
index 9f95887..e11f35c 100644
--- a/mlir/examples/toy/Ch4/toyc.cpp
+++ b/mlir/examples/toy/Ch4/toyc.cpp
@@ -103,10 +103,10 @@ int loadMLIR(llvm::SourceMgr &sourceMgr, mlir::MLIRContext &context,
 }
 
 int dumpMLIR() {
-  mlir::MLIRContext context(/*loadAllDialects=*/false);
-  // Load our Dialect in this MLIR Context.
-  context.getOrLoadDialect<mlir::toy::ToyDialect>();
+  // Register our Dialect with MLIR.
+  mlir::registerDialect<mlir::toy::ToyDialect>();
 
+  mlir::MLIRContext context;
   mlir::OwningModuleRef module;
   llvm::SourceMgr sourceMgr;
   mlir::SourceMgrDiagnosticHandler sourceMgrHandler(sourceMgr, &context);
diff --git a/mlir/examples/toy/Ch5/mlir/LowerToAffineLoops.cpp b/mlir/examples/toy/Ch5/mlir/LowerToAffineLoops.cpp
index 1077fc9..3097681 100644
--- a/mlir/examples/toy/Ch5/mlir/LowerToAffineLoops.cpp
+++ b/mlir/examples/toy/Ch5/mlir/LowerToAffineLoops.cpp
@@ -256,10 +256,6 @@ struct TransposeOpLowering : public ConversionPattern {
 namespace {
 struct ToyToAffineLoweringPass
     : public PassWrapper<ToyToAffineLoweringPass, FunctionPass> {
-  void getDependentDialects(DialectRegistry &registry) const override {
-    registry.insert<AffineDialect>();
-    registry.insert<StandardOpsDialect>();
-  }
   void runOnFunction() final;
 };
 } // end anonymous namespace.
diff --git a/mlir/examples/toy/Ch5/toyc.cpp b/mlir/examples/toy/Ch5/toyc.cpp
index 16faac0..ed04969 100644
--- a/mlir/examples/toy/Ch5/toyc.cpp
+++ b/mlir/examples/toy/Ch5/toyc.cpp
@@ -106,10 +106,10 @@ int loadMLIR(llvm::SourceMgr &sourceMgr, mlir::MLIRContext &context,
 }
 
 int dumpMLIR() {
-  mlir::MLIRContext context(/*loadAllDialects=*/false);
-  // Load our Dialect in this MLIR Context.
-  context.getOrLoadDialect<mlir::toy::ToyDialect>();
+  // Register our Dialect with MLIR.
+  mlir::registerDialect<mlir::toy::ToyDialect>();
 
+  mlir::MLIRContext context;
   mlir::OwningModuleRef module;
   llvm::SourceMgr sourceMgr;
   mlir::SourceMgrDiagnosticHandler sourceMgrHandler(sourceMgr, &context);
diff --git a/mlir/examples/toy/Ch6/mlir/LowerToAffineLoops.cpp b/mlir/examples/toy/Ch6/mlir/LowerToAffineLoops.cpp
index 9ff9eb4..cac3415 100644
--- a/mlir/examples/toy/Ch6/mlir/LowerToAffineLoops.cpp
+++ b/mlir/examples/toy/Ch6/mlir/LowerToAffineLoops.cpp
@@ -255,10 +255,6 @@ struct TransposeOpLowering : public ConversionPattern {
 namespace {
 struct ToyToAffineLoweringPass
     : public PassWrapper<ToyToAffineLoweringPass, FunctionPass> {
-  void getDependentDialects(DialectRegistry &registry) const override {
-    registry.insert<AffineDialect>();
-    registry.insert<StandardOpsDialect>();
-  }
   void runOnFunction() final;
 };
 } // end anonymous namespace.
diff --git a/mlir/examples/toy/Ch6/mlir/LowerToLLVM.cpp b/mlir/examples/toy/Ch6/mlir/LowerToLLVM.cpp
index 8020fb3..74b32dc 100644
--- a/mlir/examples/toy/Ch6/mlir/LowerToLLVM.cpp
+++ b/mlir/examples/toy/Ch6/mlir/LowerToLLVM.cpp
@@ -159,10 +159,6 @@ private:
 namespace {
 struct ToyToLLVMLoweringPass
     : public PassWrapper<ToyToLLVMLoweringPass, OperationPass<ModuleOp>> {
-  void getDependentDialects(DialectRegistry &registry) const override {
-    registry.insert<LLVM::LLVMDialect>();
-    registry.insert<scf::SCFDialect>();
-  }
   void runOnOperation() final;
 };
 } // end anonymous namespace
diff --git a/mlir/examples/toy/Ch6/toyc.cpp b/mlir/examples/toy/Ch6/toyc.cpp
index 9504a38..bdcdf1a 100644
--- a/mlir/examples/toy/Ch6/toyc.cpp
+++ b/mlir/examples/toy/Ch6/toyc.cpp
@@ -255,10 +255,10 @@ int main(int argc, char **argv) {
 
   // If we aren't dumping the AST, then we are compiling with/to MLIR.
 
-  mlir::MLIRContext context(/*loadAllDialects=*/false);
-  // Load our Dialect in this MLIR Context.
-  context.getOrLoadDialect<mlir::toy::ToyDialect>();
+  // Register our Dialect with MLIR.
+  mlir::registerDialect<mlir::toy::ToyDialect>();
 
+  mlir::MLIRContext context;
   mlir::OwningModuleRef module;
   if (int error = loadAndProcessMLIR(context, module))
     return error;
diff --git a/mlir/examples/toy/Ch7/mlir/LowerToAffineLoops.cpp b/mlir/examples/toy/Ch7/mlir/LowerToAffineLoops.cpp
index 1077fc9..3097681 100644
--- a/mlir/examples/toy/Ch7/mlir/LowerToAffineLoops.cpp
+++ b/mlir/examples/toy/Ch7/mlir/LowerToAffineLoops.cpp
@@ -256,10 +256,6 @@ struct TransposeOpLowering : public ConversionPattern {
 namespace {
 struct ToyToAffineLoweringPass
     : public PassWrapper<ToyToAffineLoweringPass, FunctionPass> {
-  void getDependentDialects(DialectRegistry &registry) const override {
-    registry.insert<AffineDialect>();
-    registry.insert<StandardOpsDialect>();
-  }
   void runOnFunction() final;
 };
 } // end anonymous namespace.
diff --git a/mlir/examples/toy/Ch7/mlir/LowerToLLVM.cpp b/mlir/examples/toy/Ch7/mlir/LowerToLLVM.cpp
index 8020fb3..74b32dc 100644
--- a/mlir/examples/toy/Ch7/mlir/LowerToLLVM.cpp
+++ b/mlir/examples/toy/Ch7/mlir/LowerToLLVM.cpp
@@ -159,10 +159,6 @@ private:
 namespace {
 struct ToyToLLVMLoweringPass
     : public PassWrapper<ToyToLLVMLoweringPass, OperationPass<ModuleOp>> {
-  void getDependentDialects(DialectRegistry &registry) const override {
-    registry.insert<LLVM::LLVMDialect>();
-    registry.insert<scf::SCFDialect>();
-  }
   void runOnOperation() final;
 };
 } // end anonymous namespace
diff --git a/mlir/examples/toy/Ch7/toyc.cpp b/mlir/examples/toy/Ch7/toyc.cpp
index cb3b455..c1cc207 100644
--- a/mlir/examples/toy/Ch7/toyc.cpp
+++ b/mlir/examples/toy/Ch7/toyc.cpp
@@ -256,10 +256,10 @@ int main(int argc, char **argv) {
 
   // If we aren't dumping the AST, then we are compiling with/to MLIR.
 
-  mlir::MLIRContext context(/*loadAllDialects=*/false);
-  // Load our Dialect in this MLIR Context.
-  context.getOrLoadDialect<mlir::toy::ToyDialect>();
+  // Register our Dialect with MLIR.
+  mlir::registerDialect<mlir::toy::ToyDialect>();
 
+  mlir::MLIRContext context;
   mlir::OwningModuleRef module;
   if (int error = loadAndProcessMLIR(context, module))
     return error;
diff --git a/mlir/include/mlir-c/IR.h b/mlir/include/mlir-c/IR.h
index f9ec4d1..6b5be2d 100644
--- a/mlir/include/mlir-c/IR.h
+++ b/mlir/include/mlir-c/IR.h
@@ -90,12 +90,6 @@ MlirContext mlirContextCreate();
 /** Takes an MLIR context owned by the caller and destroys it. */
 void mlirContextDestroy(MlirContext context);
 
-/** Load all the globally registered dialects in the provided context.
- *  TODO: remove the concept of globally registered dialect by exposing the
- *  DialectRegistry.
- */
-void mlirContextLoadAllDialects(MlirContext context);
-
 /*============================================================================*/
 /* Location API.                                                              */
 /*============================================================================*/
diff --git a/mlir/include/mlir/Conversion/Passes.td b/mlir/include/mlir/Conversion/Passes.td
index 0c40bb3..4d4fe06 100644
--- a/mlir/include/mlir/Conversion/Passes.td
+++ b/mlir/include/mlir/Conversion/Passes.td
@@ -66,11 +66,6 @@ def ConvertAffineToStandard : Pass<"lower-affine"> {
         `affine.apply`.
   }];
   let constructor = "mlir::createLowerAffinePass()";
-  let dependentDialects = [
-    "scf::SCFDialect",
-    "StandardOpsDialect",
-    "vector::VectorDialect"
-  ];
 }
 
 //===----------------------------------------------------------------------===//
@@ -81,7 +76,6 @@ def ConvertAVX512ToLLVM : Pass<"convert-avx512-to-llvm", "ModuleOp"> {
   let summary = "Convert the operations from the avx512 dialect into the LLVM "
                 "dialect";
   let constructor = "mlir::createConvertAVX512ToLLVMPass()";
-  let dependentDialects = ["LLVM::LLVMDialect", "LLVM::LLVMAVX512Dialect"];
 }
 
 //===----------------------------------------------------------------------===//
@@ -104,7 +98,6 @@ def GpuToLLVMConversionPass : Pass<"gpu-to-llvm", "ModuleOp"> {
 def ConvertGpuOpsToNVVMOps : Pass<"convert-gpu-to-nvvm", "gpu::GPUModuleOp"> {
   let summary = "Generate NVVM operations for gpu operations";
   let constructor = "mlir::createLowerGpuOpsToNVVMOpsPass()";
-  let dependentDialects = ["NVVM::NVVMDialect"];
   let options = [
     Option<"indexBitwidth", "index-bitwidth", "unsigned",
            /*default=kDeriveIndexBitwidthFromDataLayout*/"0",
@@ -119,7 +112,6 @@ def ConvertGpuOpsToNVVMOps : Pass<"convert-gpu-to-nvvm", "gpu::GPUModuleOp"> {
 def ConvertGpuOpsToROCDLOps : Pass<"convert-gpu-to-rocdl", "gpu::GPUModuleOp"> {
   let summary = "Generate ROCDL operations for gpu operations";
   let constructor = "mlir::createLowerGpuOpsToROCDLOpsPass()";
-  let dependentDialects = ["ROCDL::ROCDLDialect"];
   let options = [
     Option<"indexBitwidth", "index-bitwidth", "unsigned",
            /*default=kDeriveIndexBitwidthFromDataLayout*/"0",
@@ -134,7 +126,6 @@ def ConvertGpuOpsToROCDLOps : Pass<"convert-gpu-to-rocdl", "gpu::GPUModuleOp"> {
 def ConvertGPUToSPIRV : Pass<"convert-gpu-to-spirv", "ModuleOp"> {
   let summary = "Convert GPU dialect to SPIR-V dialect";
   let constructor = "mlir::createConvertGPUToSPIRVPass()";
-  let dependentDialects = ["spirv::SPIRVDialect"];
 }
 
 //===----------------------------------------------------------------------===//
@@ -145,7 +136,6 @@ def ConvertGpuLaunchFuncToVulkanLaunchFunc
     : Pass<"convert-gpu-launch-to-vulkan-launch", "ModuleOp"> {
   let summary = "Convert gpu.launch_func to vulkanLaunch external call";
   let constructor = "mlir::createConvertGpuLaunchFuncToVulkanLaunchFuncPass()";
-  let dependentDialects = ["spirv::SPIRVDialect"];
 }
 
 def ConvertVulkanLaunchFuncToVulkanCalls
@@ -153,7 +143,6 @@ def ConvertVulkanLaunchFuncToVulkanCalls
   let summary = "Convert vulkanLaunch external call to Vulkan runtime external "
                 "calls";
   let constructor = "mlir::createConvertVulkanLaunchFuncToVulkanCallsPass()";
-  let dependentDialects = ["LLVM::LLVMDialect"];
 }
 
 //===----------------------------------------------------------------------===//
@@ -164,7 +153,6 @@ def ConvertLinalgToLLVM : Pass<"convert-linalg-to-llvm", "ModuleOp"> {
   let summary = "Convert the operations from the linalg dialect into the LLVM "
                 "dialect";
   let constructor = "mlir::createConvertLinalgToLLVMPass()";
-  let dependentDialects = ["scf::SCFDialect", "LLVM::LLVMDialect"];
 }
 
 //===----------------------------------------------------------------------===//
@@ -175,7 +163,6 @@ def ConvertLinalgToStandard : Pass<"convert-linalg-to-std", "ModuleOp"> {
   let summary = "Convert the operations from the linalg dialect into the "
                 "Standard dialect";
   let constructor = "mlir::createConvertLinalgToStandardPass()";
-  let dependentDialects = ["StandardOpsDialect"];
 }
 
 //===----------------------------------------------------------------------===//
@@ -185,7 +172,6 @@ def ConvertLinalgToStandard : Pass<"convert-linalg-to-std", "ModuleOp"> {
 def ConvertLinalgToSPIRV : Pass<"convert-linalg-to-spirv", "ModuleOp"> {
   let summary = "Convert Linalg ops to SPIR-V ops";
   let constructor = "mlir::createLinalgToSPIRVPass()";
-  let dependentDialects = ["spirv::SPIRVDialect"];
 }
 
 //===----------------------------------------------------------------------===//
@@ -196,7 +182,6 @@ def SCFToStandard : Pass<"convert-scf-to-std"> {
   let summary = "Convert SCF dialect to Standard dialect, replacing structured"
                 " control flow with a CFG";
   let constructor = "mlir::createLowerToCFGPass()";
-  let dependentDialects = ["StandardOpsDialect"];
 }
 
 //===----------------------------------------------------------------------===//
@@ -206,7 +191,6 @@ def SCFToStandard : Pass<"convert-scf-to-std"> {
 def ConvertAffineForToGPU : FunctionPass<"convert-affine-for-to-gpu"> {
   let summary = "Convert top-level AffineFor Ops to GPU kernels";
   let constructor = "mlir::createAffineForToGPUPass()";
-  let dependentDialects = ["gpu::GPUDialect"];
   let options = [
     Option<"numBlockDims", "gpu-block-dims", "unsigned", /*default=*/"1u",
            "Number of GPU block dimensions for mapping">,
@@ -218,7 +202,6 @@ def ConvertAffineForToGPU : FunctionPass<"convert-affine-for-to-gpu"> {
 def ConvertParallelLoopToGpu : Pass<"convert-parallel-loops-to-gpu"> {
   let summary = "Convert mapped scf.parallel ops to gpu launch operations";
   let constructor = "mlir::createParallelLoopToGpuPass()";
-  let dependentDialects = ["AffineDialect", "gpu::GPUDialect"];
 }
 
 //===----------------------------------------------------------------------===//
@@ -229,7 +212,6 @@ def ConvertShapeToStandard : Pass<"convert-shape-to-std", "ModuleOp"> {
   let summary = "Convert operations from the shape dialect into the standard "
                 "dialect";
   let constructor = "mlir::createConvertShapeToStandardPass()";
-  let dependentDialects = ["StandardOpsDialect"];
 }
 
 //===----------------------------------------------------------------------===//
@@ -239,7 +221,6 @@ def ConvertShapeToStandard : Pass<"convert-shape-to-std", "ModuleOp"> {
 def ConvertShapeToSCF : FunctionPass<"convert-shape-to-scf"> {
   let summary = "Convert operations from the shape dialect to the SCF dialect";
   let constructor = "mlir::createConvertShapeToSCFPass()";
-  let dependentDialects = ["scf::SCFDialect"];
 }
 
 //===----------------------------------------------------------------------===//
@@ -249,7 +230,6 @@ def ConvertShapeToSCF : FunctionPass<"convert-shape-to-scf"> {
 def ConvertSPIRVToLLVM : Pass<"convert-spirv-to-llvm", "ModuleOp"> {
   let summary = "Convert SPIR-V dialect to LLVM dialect";
   let constructor = "mlir::createConvertSPIRVToLLVMPass()";
-  let dependentDialects = ["LLVM::LLVMDialect"];
 }
 
 //===----------------------------------------------------------------------===//
@@ -284,7 +264,6 @@ def ConvertStandardToLLVM : Pass<"convert-std-to-llvm", "ModuleOp"> {
     LLVM IR types.
   }];
   let constructor = "mlir::createLowerToLLVMPass()";
-  let dependentDialects = ["LLVM::LLVMDialect"];
   let options = [
     Option<"useAlignedAlloc", "use-aligned-alloc", "bool", /*default=*/"false",
            "Use aligned_alloc in place of malloc for heap allocations">,
@@ -308,13 +287,11 @@ def ConvertStandardToLLVM : Pass<"convert-std-to-llvm", "ModuleOp"> {
 def LegalizeStandardForSPIRV : Pass<"legalize-std-for-spirv"> {
   let summary = "Legalize standard ops for SPIR-V lowering";
   let constructor = "mlir::createLegalizeStdOpsForSPIRVLoweringPass()";
-  let dependentDialects = ["spirv::SPIRVDialect"];
 }
 
 def ConvertStandardToSPIRV : Pass<"convert-std-to-spirv", "ModuleOp"> {
   let summary = "Convert Standard Ops to SPIR-V dialect";
   let constructor = "mlir::createConvertStandardToSPIRVPass()";
-  let dependentDialects = ["spirv::SPIRVDialect"];
 }
 
 //===----------------------------------------------------------------------===//
@@ -325,7 +302,6 @@ def ConvertVectorToSCF : FunctionPass<"convert-vector-to-scf"> {
   let summary = "Lower the operations from the vector dialect into the SCF "
                 "dialect";
   let constructor = "mlir::createConvertVectorToSCFPass()";
-  let dependentDialects = ["AffineDialect", "scf::SCFDialect"];
   let options = [
     Option<"fullUnroll", "full-unroll", "bool", /*default=*/"false",
            "Perform full unrolling when converting vector transfers to SCF">,
@@ -340,7 +316,6 @@ def ConvertVectorToLLVM : Pass<"convert-vector-to-llvm", "ModuleOp"> {
   let summary = "Lower the operations from the vector dialect into the LLVM "
                 "dialect";
   let constructor = "mlir::createConvertVectorToLLVMPass()";
-  let dependentDialects = ["LLVM::LLVMDialect"];
   let options = [
     Option<"reassociateFPReductions", "reassociate-fp-reductions",
            "bool", /*default=*/"false",
@@ -356,7 +331,6 @@ def ConvertVectorToROCDL : Pass<"convert-vector-to-rocdl", "ModuleOp"> {
   let summary = "Lower the operations from the vector dialect into the ROCDL "
                 "dialect";
   let constructor = "mlir::createConvertVectorToROCDLPass()";
-  let dependentDialects = ["ROCDL::ROCDLDialect"];
 }
 
 #endif // MLIR_CONVERSION_PASSES
diff --git a/mlir/include/mlir/Dialect/Affine/Passes.td b/mlir/include/mlir/Dialect/Affine/Passes.td
index f43fabd..8106400 100644
--- a/mlir/include/mlir/Dialect/Affine/Passes.td
+++ b/mlir/include/mlir/Dialect/Affine/Passes.td
@@ -94,7 +94,6 @@ def AffineLoopUnrollAndJam : FunctionPass<"affine-loop-unroll-jam"> {
 def AffineVectorize : FunctionPass<"affine-super-vectorize"> {
   let summary = "Vectorize to a target independent n-D vector abstraction";
   let constructor = "mlir::createSuperVectorizePass()";
-  let dependentDialects = ["vector::VectorDialect"];
   let options = [
     ListOption<"vectorSizes", "virtual-vector-size", "int64_t",
                "Specify an n-D virtual vector size for vectorization",
diff --git a/mlir/include/mlir/Dialect/LLVMIR/LLVMDialect.h b/mlir/include/mlir/Dialect/LLVMIR/LLVMDialect.h
index 2f465f0..04700f0 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/LLVMDialect.h
+++ b/mlir/include/mlir/Dialect/LLVMIR/LLVMDialect.h
@@ -15,7 +15,6 @@
 #define MLIR_DIALECT_LLVMIR_LLVMDIALECT_H_
 
 #include "mlir/Dialect/LLVMIR/LLVMTypes.h"
-#include "mlir/Dialect/OpenMP/OpenMPDialect.h"
 #include "mlir/IR/Dialect.h"
 #include "mlir/IR/Function.h"
 #include "mlir/IR/OpDefinition.h"
diff --git a/mlir/include/mlir/Dialect/LLVMIR/LLVMOpBase.td b/mlir/include/mlir/Dialect/LLVMIR/LLVMOpBase.td
index 2617a2d..d21f5bc 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/LLVMOpBase.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/LLVMOpBase.td
@@ -19,11 +19,6 @@ include "mlir/IR/OpBase.td"
 def LLVM_Dialect : Dialect {
   let name = "llvm";
   let cppNamespace = "LLVM";
-
-  /// FIXME: at the moment this is a dependency of the translation to LLVM IR,
-  /// not really one of this dialect per-se.
-  let dependentDialects = [ "omp::OpenMPDialect" ];
-
   let hasRegionArgAttrVerify = 1;
   let extraClassDeclaration = [{
     ~LLVMDialect();
diff --git a/mlir/include/mlir/Dialect/LLVMIR/NVVMDialect.h b/mlir/include/mlir/Dialect/LLVMIR/NVVMDialect.h
index 9cc5314..86d437c 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/NVVMDialect.h
+++ b/mlir/include/mlir/Dialect/LLVMIR/NVVMDialect.h
@@ -14,7 +14,6 @@
 #ifndef MLIR_DIALECT_LLVMIR_NVVMDIALECT_H_
 #define MLIR_DIALECT_LLVMIR_NVVMDIALECT_H_
 
-#include "mlir/Dialect/LLVMIR/LLVMDialect.h"
 #include "mlir/IR/Dialect.h"
 #include "mlir/IR/OpDefinition.h"
 #include "mlir/Interfaces/SideEffectInterfaces.h"
diff --git a/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td b/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
index 0e5bc16..5f022e32 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
@@ -23,7 +23,6 @@ include "mlir/Interfaces/SideEffectInterfaces.td"
 def NVVM_Dialect : Dialect {
   let name = "nvvm";
   let cppNamespace = "NVVM";
-  let dependentDialects = [ "LLVM::LLVMDialect" ];
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/mlir/include/mlir/Dialect/LLVMIR/ROCDLDialect.h b/mlir/include/mlir/Dialect/LLVMIR/ROCDLDialect.h
index eb40373..bf761c3 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/ROCDLDialect.h
+++ b/mlir/include/mlir/Dialect/LLVMIR/ROCDLDialect.h
@@ -22,7 +22,6 @@
 #ifndef MLIR_DIALECT_LLVMIR_ROCDLDIALECT_H_
 #define MLIR_DIALECT_LLVMIR_ROCDLDIALECT_H_
 
-#include "mlir/Dialect/LLVMIR/LLVMDialect.h"
 #include "mlir/IR/Dialect.h"
 #include "mlir/IR/OpDefinition.h"
 #include "mlir/Interfaces/SideEffectInterfaces.h"
diff --git a/mlir/include/mlir/Dialect/LLVMIR/ROCDLOps.td b/mlir/include/mlir/Dialect/LLVMIR/ROCDLOps.td
index f9aca5a..0cd1169 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/ROCDLOps.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/ROCDLOps.td
@@ -23,7 +23,6 @@ include "mlir/Interfaces/SideEffectInterfaces.td"
 def ROCDL_Dialect : Dialect {
   let name = "rocdl";
   let cppNamespace = "ROCDL";
-  let dependentDialects = [ "LLVM::LLVMDialect" ];
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/mlir/include/mlir/Dialect/Linalg/Passes.td b/mlir/include/mlir/Dialect/Linalg/Passes.td
index dcf4b5e..11f12ad 100644
--- a/mlir/include/mlir/Dialect/Linalg/Passes.td
+++ b/mlir/include/mlir/Dialect/Linalg/Passes.td
@@ -30,20 +30,17 @@ def LinalgFusion : FunctionPass<"linalg-fusion"> {
 def LinalgFusionOfTensorOps : Pass<"linalg-fusion-for-tensor-ops"> {
   let summary = "Fuse operations on RankedTensorType in linalg dialect";
   let constructor = "mlir::createLinalgFusionOfTensorOpsPass()";
-  let dependentDialects = ["AffineDialect"];
 }
 
 def LinalgLowerToAffineLoops : FunctionPass<"convert-linalg-to-affine-loops"> {
   let summary = "Lower the operations from the linalg dialect into affine "
                 "loops";
   let constructor = "mlir::createConvertLinalgToAffineLoopsPass()";
-  let dependentDialects = ["AffineDialect"];
 }
 
 def LinalgLowerToLoops : FunctionPass<"convert-linalg-to-loops"> {
   let summary = "Lower the operations from the linalg dialect into loops";
   let constructor = "mlir::createConvertLinalgToLoopsPass()";
-  let dependentDialects = ["scf::SCFDialect", "AffineDialect"];
 }
 
 def LinalgOnTensorsToBuffers : Pass<"convert-linalg-on-tensors-to-buffers", "ModuleOp"> {
@@ -57,7 +54,6 @@ def LinalgLowerToParallelLoops
   let summary = "Lower the operations from the linalg dialect into parallel "
                 "loops";
   let constructor = "mlir::createConvertLinalgToParallelLoopsPass()";
-  let dependentDialects = ["AffineDialect", "scf::SCFDialect"];
 }
 
 def LinalgPromotion : FunctionPass<"linalg-promote-subviews"> {
@@ -74,9 +70,6 @@ def LinalgPromotion : FunctionPass<"linalg-promote-subviews"> {
 def LinalgTiling : FunctionPass<"linalg-tile"> {
   let summary = "Tile operations in the linalg dialect";
   let constructor = "mlir::createLinalgTilingPass()";
-  let dependentDialects = [
-    "AffineDialect", "scf::SCFDialect"
-  ];
   let options = [
     ListOption<"tileSizes", "linalg-tile-sizes", "int64_t",
                "Test generation of dynamic promoted buffers",
@@ -93,7 +86,6 @@ def LinalgTilingToParallelLoops
                "Test generation of dynamic promoted buffers",
                "llvm::cl::ZeroOrMore, llvm::cl::MiscFlags::CommaSeparated">
   ];
-  let dependentDialects = ["AffineDialect", "scf::SCFDialect"];
 }
 
 #endif // MLIR_DIALECT_LINALG_PASSES
diff --git a/mlir/include/mlir/Dialect/SCF/Passes.td b/mlir/include/mlir/Dialect/SCF/Passes.td
index 6f3cf0e..483d0ba 100644
--- a/mlir/include/mlir/Dialect/SCF/Passes.td
+++ b/mlir/include/mlir/Dialect/SCF/Passes.td
@@ -36,7 +36,6 @@ def SCFParallelLoopTiling : FunctionPass<"parallel-loop-tiling"> {
                "Factors to tile parallel loops by",
                "llvm::cl::ZeroOrMore, llvm::cl::MiscFlags::CommaSeparated">
   ];
-  let dependentDialects = ["AffineDialect"];
 }
 
 #endif // MLIR_DIALECT_SCF_PASSES
diff --git a/mlir/include/mlir/IR/Dialect.h b/mlir/include/mlir/IR/Dialect.h
index d00d86db..4f9e4cb 100644
--- a/mlir/include/mlir/IR/Dialect.h
+++ b/mlir/include/mlir/IR/Dialect.h
@@ -16,8 +16,6 @@
 #include "mlir/IR/OperationSupport.h"
 #include "mlir/Support/TypeID.h"
 
-#include <map>
-
 namespace mlir {
 class DialectAsmParser;
 class DialectAsmPrinter;
@@ -25,7 +23,7 @@ class DialectInterface;
 class OpBuilder;
 class Type;
 
-using DialectAllocatorFunction = std::function<Dialect *(MLIRContext *)>;
+using DialectAllocatorFunction = std::function<void(MLIRContext *)>;
 
 /// Dialects are groups of MLIR operations and behavior associated with the
 /// entire group.  For example, hooks into other systems for constant folding,
@@ -214,81 +212,30 @@ private:
   /// A collection of registered dialect interfaces.
   DenseMap<TypeID, std::unique_ptr<DialectInterface>> registeredInterfaces;
 
+  /// Registers a specific dialect creation function with the global registry.
+  /// Used through the registerDialect template.
+  /// Registrations are deduplicated by dialect TypeID and only the first
+  /// registration will be used.
+  static void
+  registerDialectAllocator(TypeID typeID,
+                           const DialectAllocatorFunction &function);
+  template <typename ConcreteDialect>
   friend void registerDialect();
   friend class MLIRContext;
 };
 
-/// The DialectRegistry maps a dialect namespace to a constructor for the
-/// matching dialect.
-/// This allows for decoupling the list of dialects "available" from the
-/// dialects loaded in the Context. The parser in particular will lazily load
-/// dialects in in the Context as operations are encountered.
-class DialectRegistry {
-  using MapTy =
-      std::map<std::string, std::pair<TypeID, DialectAllocatorFunction>>;
-
-public:
-  template <typename ConcreteDialect> void insert() {
-    insert(TypeID::get<ConcreteDialect>(),
-           ConcreteDialect::getDialectNamespace(),
-           static_cast<DialectAllocatorFunction>(([](MLIRContext *ctx) {
-             // Just allocate the dialect, the context
-             // takes ownership of it.
-             return ctx->getOrLoadDialect<ConcreteDialect>();
-           })));
-  }
-
-  /// Add a new dialect constructor to the registry.
-  void insert(TypeID typeID, StringRef name, DialectAllocatorFunction ctor);
-
-  /// Load a dialect for this namespace in the provided context.
-  Dialect *loadByName(StringRef name, MLIRContext *context);
-
-  // Register all dialects available in the current registry with the registry
-  // in the provided context.
-  void appendTo(DialectRegistry &destination) {
-    for (const auto &name_and_registration_it : registry)
-      destination.insert(name_and_registration_it.second.first,
-                         name_and_registration_it.first,
-                         name_and_registration_it.second.second);
-  }
-  // Load all dialects available in the registry in the provided context.
-  void loadAll(MLIRContext *context) {
-    for (const auto &name_and_registration_it : registry)
-      name_and_registration_it.second.second(context);
-  }
-
-  MapTy::const_iterator begin() const { return registry.begin(); }
-  MapTy::const_iterator end() const { return registry.end(); }
-
-private:
-  MapTy registry;
-};
-
-/// Deprecated: this provides a global registry for convenience, while we're
-/// transitionning the registration mechanism to a stateless approach.
-DialectRegistry &getGlobalDialectRegistry();
-
-/// Registers all dialects from the global registries with the
-/// specified MLIRContext. This won't load the dialects in the context,
-/// but only make them available for lazy loading by name.
+/// Registers all dialects and hooks from the global registries with the
+/// specified MLIRContext.
 /// Note: This method is not thread-safe.
-inline void registerAllDialects(MLIRContext *context) {
-  getGlobalDialectRegistry().appendTo(context->getDialectRegistry());
-}
-
-/// Register and return the dialect with the given namespace in the provided
-/// context. Returns nullptr is there is no constructor registered for this
-/// dialect.
-inline Dialect *registerDialect(StringRef name, MLIRContext *context) {
-  return getGlobalDialectRegistry().loadByName(name, context);
-}
+void registerAllDialects(MLIRContext *context);
 
 /// Utility to register a dialect. Client can register their dialect with the
 /// global registry by calling registerDialect<MyDialect>();
 /// Note: This method is not thread-safe.
 template <typename ConcreteDialect> void registerDialect() {
-  getGlobalDialectRegistry().insert<ConcreteDialect>();
+  Dialect::registerDialectAllocator(
+      TypeID::get<ConcreteDialect>(),
+      [](MLIRContext *ctx) { ctx->getOrCreateDialect<ConcreteDialect>(); });
 }
 
 /// DialectRegistration provides a global initializer that registers a Dialect
diff --git a/mlir/include/mlir/IR/FunctionSupport.h b/mlir/include/mlir/IR/FunctionSupport.h
index 3d467cd..7e281f3 100644
--- a/mlir/include/mlir/IR/FunctionSupport.h
+++ b/mlir/include/mlir/IR/FunctionSupport.h
@@ -428,7 +428,7 @@ LogicalResult FunctionLike<ConcreteType>::verifyTrait(Operation *op) {
       if (!attr.first.strref().contains('.'))
         return funcOp.emitOpError("arguments may only have dialect attributes");
       auto dialectNamePair = attr.first.strref().split('.');
-      if (auto *dialect = ctx->getLoadedDialect(dialectNamePair.first)) {
+      if (auto *dialect = ctx->getRegisteredDialect(dialectNamePair.first)) {
         if (failed(dialect->verifyRegionArgAttribute(op, /*regionIndex=*/0,
                                                      /*argIndex=*/i, attr)))
           return failure();
@@ -444,7 +444,7 @@ LogicalResult FunctionLike<ConcreteType>::verifyTrait(Operation *op) {
       if (!attr.first.strref().contains('.'))
         return funcOp.emitOpError("results may only have dialect attributes");
       auto dialectNamePair = attr.first.strref().split('.');
-      if (auto *dialect = ctx->getLoadedDialect(dialectNamePair.first)) {
+      if (auto *dialect = ctx->getRegisteredDialect(dialectNamePair.first)) {
         if (failed(dialect->verifyRegionResultAttribute(op, /*regionIndex=*/0,
                                                         /*resultIndex=*/i,
                                                         attr)))
diff --git a/mlir/include/mlir/IR/MLIRContext.h b/mlir/include/mlir/IR/MLIRContext.h
index d406c30..0192a8a 100644
--- a/mlir/include/mlir/IR/MLIRContext.h
+++ b/mlir/include/mlir/IR/MLIRContext.h
@@ -19,12 +19,10 @@ namespace mlir {
 class AbstractOperation;
 class DiagnosticEngine;
 class Dialect;
-class DialectRegistry;
 class InFlightDiagnostic;
 class Location;
 class MLIRContextImpl;
 class StorageUniquer;
-DialectRegistry &getGlobalDialectRegistry();
 
 /// MLIRContext is the top-level object for a collection of MLIR modules.  It
 /// holds immortal uniqued objects like types, and the tables used to unique
@@ -36,54 +34,34 @@ DialectRegistry &getGlobalDialectRegistry();
 ///
 class MLIRContext {
 public:
-  /// Create a new Context.
-  /// The loadAllDialects parameters allows to load all dialects from the global
-  /// registry on Context construction. It is deprecated and will be removed
-  /// soon.
-  explicit MLIRContext(bool loadAllDialects = true);
+  explicit MLIRContext();
   ~MLIRContext();
 
-  /// Return information about all IR dialects loaded in the context.
-  std::vector<Dialect *> getLoadedDialects();
-
-  /// Return the dialect registry associated with this context.
-  DialectRegistry &getDialectRegistry();
-
-  /// Return information about all available dialects in the registry in this
-  /// context.
-  std::vector<StringRef> getAvailableDialects();
+  /// Return information about all registered IR dialects.
+  std::vector<Dialect *> getRegisteredDialects();
 
   /// Get a registered IR dialect with the given namespace. If an exact match is
   /// not found, then return nullptr.
-  Dialect *getLoadedDialect(StringRef name);
+  Dialect *getRegisteredDialect(StringRef name);
 
   /// Get a registered IR dialect for the given derived dialect type. The
   /// derived type must provide a static 'getDialectNamespace' method.
-  template <typename T> T *getLoadedDialect() {
-    return static_cast<T *>(getLoadedDialect(T::getDialectNamespace()));
+  template <typename T> T *getRegisteredDialect() {
+    return static_cast<T *>(getRegisteredDialect(T::getDialectNamespace()));
   }
 
   /// Get (or create) a dialect for the given derived dialect type. The derived
   /// type must provide a static 'getDialectNamespace' method.
-  template <typename T> T *getOrLoadDialect() {
-    return static_cast<T *>(
-        getOrLoadDialect(T::getDialectNamespace(), TypeID::get<T>(), [this]() {
+  template <typename T>
+  T *getOrCreateDialect() {
+    return static_cast<T *>(getOrCreateDialect(
+        T::getDialectNamespace(), TypeID::get<T>(), [this]() {
           std::unique_ptr<T> dialect(new T(this));
+          dialect->dialectID = TypeID::get<T>();
           return dialect;
         }));
   }
 
-  /// Deprecated: load all globally registered dialects into this context.
-  /// This method will be removed soon, it can be used temporarily as we're
-  /// phasing out the global registry.
-  void loadAllGloballyRegisteredDialects();
-
-  /// Get (or create) a dialect for the given derived dialect name.
-  /// The dialect will be loaded from the registry if no dialect is found.
-  /// If no dialect is loaded for this name and none is available in the
-  /// registry, returns nullptr.
-  Dialect *getOrLoadDialect(StringRef name);
-
   /// Return true if we allow to create operation for unregistered dialects.
   bool allowsUnregisteredDialects();
 
@@ -145,12 +123,10 @@ private:
   const std::unique_ptr<MLIRContextImpl> impl;
 
   /// Get a dialect for the provided namespace and TypeID: abort the program if
-  /// a dialect exist for this namespace with different TypeID. If a dialect has
-  /// not been loaded for this namespace/TypeID yet, use the provided ctor to
-  /// create one on the fly and load it. Returns a pointer to the dialect owned
-  /// by the context.
-  Dialect *getOrLoadDialect(StringRef dialectNamespace, TypeID dialectID,
-                            function_ref<std::unique_ptr<Dialect>()> ctor);
+  /// a dialect exist for this namespace with different TypeID. Returns a
+  /// pointer to the dialect owned by the context.
+  Dialect *getOrCreateDialect(StringRef dialectNamespace, TypeID dialectID,
+                              function_ref<std::unique_ptr<Dialect>()> ctor);
 
   MLIRContext(const MLIRContext &) = delete;
   void operator=(const MLIRContext &) = delete;
diff --git a/mlir/include/mlir/IR/OpBase.td b/mlir/include/mlir/IR/OpBase.td
index a28410f..9cc57a6 100644
--- a/mlir/include/mlir/IR/OpBase.td
+++ b/mlir/include/mlir/IR/OpBase.td
@@ -244,11 +244,6 @@ class Dialect {
   // The description of the dialect.
   string description = ?;
 
-  // A list of dialects this dialect will load on construction as dependencies.
-  // These are dialects that this dialect may involved in canonicalization
-  // pattern or interfaces.
-  list<string> dependentDialects = [];
-
   // The C++ namespace that ops of this dialect should be placed into.
   //
   // By default, uses the name of the dialect as the only namespace. To avoid
diff --git a/mlir/include/mlir/InitAllDialects.h b/mlir/include/mlir/InitAllDialects.h
index a456616..b76b26f 100644
--- a/mlir/include/mlir/InitAllDialects.h
+++ b/mlir/include/mlir/InitAllDialects.h
@@ -35,32 +35,29 @@
 
 namespace mlir {
 
-// Add all the MLIR dialects to the provided registry.
-inline void registerAllDialects(DialectRegistry &registry) {
-  registry.insert<acc::OpenACCDialect>();
-  registry.insert<AffineDialect>();
-  registry.insert<avx512::AVX512Dialect>();
-  registry.insert<gpu::GPUDialect>();
-  registry.insert<LLVM::LLVMAVX512Dialect>();
-  registry.insert<LLVM::LLVMDialect>();
-  registry.insert<linalg::LinalgDialect>();
-  registry.insert<scf::SCFDialect>();
-  registry.insert<omp::OpenMPDialect>();
-  registry.insert<quant::QuantizationDialect>();
-  registry.insert<spirv::SPIRVDialect>();
-  registry.insert<StandardOpsDialect>();
-  registry.insert<vector::VectorDialect>();
-  registry.insert<NVVM::NVVMDialect>();
-  registry.insert<ROCDL::ROCDLDialect>();
-  registry.insert<SDBMDialect>();
-  registry.insert<shape::ShapeDialect>();
-}
-
 // This function should be called before creating any MLIRContext if one expect
 // all the possible dialects to be made available to the context automatically.
 inline void registerAllDialects() {
-  static bool init_once =
-      ([]() { registerAllDialects(getGlobalDialectRegistry()); }(), true);
+  static bool init_once = []() {
+    registerDialect<acc::OpenACCDialect>();
+    registerDialect<AffineDialect>();
+    registerDialect<avx512::AVX512Dialect>();
+    registerDialect<gpu::GPUDialect>();
+    registerDialect<LLVM::LLVMAVX512Dialect>();
+    registerDialect<LLVM::LLVMDialect>();
+    registerDialect<linalg::LinalgDialect>();
+    registerDialect<scf::SCFDialect>();
+    registerDialect<omp::OpenMPDialect>();
+    registerDialect<quant::QuantizationDialect>();
+    registerDialect<spirv::SPIRVDialect>();
+    registerDialect<StandardOpsDialect>();
+    registerDialect<vector::VectorDialect>();
+    registerDialect<NVVM::NVVMDialect>();
+    registerDialect<ROCDL::ROCDLDialect>();
+    registerDialect<SDBMDialect>();
+    registerDialect<shape::ShapeDialect>();
+    return true;
+  }();
   (void)init_once;
 }
 } // namespace mlir
diff --git a/mlir/include/mlir/Pass/Pass.h b/mlir/include/mlir/Pass/Pass.h
index ea361ae..7c0f9bd 100644
--- a/mlir/include/mlir/Pass/Pass.h
+++ b/mlir/include/mlir/Pass/Pass.h
@@ -9,7 +9,6 @@
 #ifndef MLIR_PASS_PASS_H
 #define MLIR_PASS_PASS_H
 
-#include "mlir/IR/Dialect.h"
 #include "mlir/IR/Function.h"
 #include "mlir/Pass/AnalysisManager.h"
 #include "mlir/Pass/PassRegistry.h"
@@ -58,13 +57,6 @@ public:
   /// Returns the derived pass name.
   virtual StringRef getName() const = 0;
 
-  /// Register dependent dialects for the current pass.
-  /// A pass is expected to register the dialects it will create operations for,
-  /// other than dialect that exists in the input. For example, a pass that
-  /// converts from Linalg to Affine would register the Affine dialect but does
-  /// not need to register Linalg.
-  virtual void getDependentDialects(DialectRegistry &registry) const {}
-
   /// Returns the command line argument used when registering this pass. Return
   /// an empty string if one does not exist.
   virtual StringRef getArgument() const {
diff --git a/mlir/include/mlir/Pass/PassBase.td b/mlir/include/mlir/Pass/PassBase.td
index 749d042..54b4403 100644
--- a/mlir/include/mlir/Pass/PassBase.td
+++ b/mlir/include/mlir/Pass/PassBase.td
@@ -78,9 +78,6 @@ class PassBase<string passArg, string base> {
   // A C++ constructor call to create an instance of this pass.
   code constructor = [{}];
 
-  // A list of dialects this pass may produce operations in.
-  list<string> dependentDialects = [];
-
   // A set of options provided by this pass.
   list<Option> options = [];
 
diff --git a/mlir/include/mlir/Pass/PassManager.h b/mlir/include/mlir/Pass/PassManager.h
index 29e7c07..9cbfb0b 100644
--- a/mlir/include/mlir/Pass/PassManager.h
+++ b/mlir/include/mlir/Pass/PassManager.h
@@ -9,7 +9,6 @@
 #ifndef MLIR_PASS_PASSMANAGER_H
 #define MLIR_PASS_PASSMANAGER_H
 
-#include "mlir/IR/Dialect.h"
 #include "mlir/IR/OperationSupport.h"
 #include "mlir/Support/LogicalResult.h"
 #include "llvm/ADT/Optional.h"
@@ -59,14 +58,6 @@ public:
   pass_iterator end();
   iterator_range<pass_iterator> getPasses() { return {begin(), end()}; }
 
-  using const_pass_iterator = llvm::pointee_iterator<
-      std::vector<std::unique_ptr<Pass>>::const_iterator>;
-  const_pass_iterator begin() const;
-  const_pass_iterator end() const;
-  iterator_range<const_pass_iterator> getPasses() const {
-    return {begin(), end()};
-  }
-
   /// Run the held passes over the given operation.
   LogicalResult run(Operation *op, AnalysisManager am);
 
@@ -109,11 +100,6 @@ public:
   /// Merge the pass statistics of this class into 'other'.
   void mergeStatisticsInto(OpPassManager &other);
 
-  /// Register dependent dialects for the current pass manager.
-  /// This is forwarding to every pass in this PassManager, see the
-  /// documentation for the same method on the Pass class.
-  void getDependentDialects(DialectRegistry &dialects) const;
-
 private:
   OpPassManager(OperationName name, bool verifyPasses);
 
diff --git a/mlir/include/mlir/Support/MlirOptMain.h b/mlir/include/mlir/Support/MlirOptMain.h
index 741276b..f235ea3 100644
--- a/mlir/include/mlir/Support/MlirOptMain.h
+++ b/mlir/include/mlir/Support/MlirOptMain.h
@@ -22,15 +22,10 @@ namespace mlir {
 struct LogicalResult;
 class PassPipelineCLParser;
 
-/// Run an passPipeline on the provided memory buffer loaded as an MLIRModule.
-/// The preloadDialectsInContext option will trigger an option upfront loading
-/// of all dialects from the global registry in the MLIRContext. This option is
-/// deprecated and will be removed soon.
 LogicalResult MlirOptMain(llvm::raw_ostream &os,
                           std::unique_ptr<llvm::MemoryBuffer> buffer,
                           const PassPipelineCLParser &passPipeline,
                           bool splitInputFile, bool verifyDiagnostics,
-                          bool verifyPasses, bool allowUnregisteredDialects,
-                          bool preloadDialectsInContext = false);
+                          bool verifyPasses, bool allowUnregisteredDialects);
 
 } // end namespace mlir
diff --git a/mlir/include/mlir/TableGen/Dialect.h b/mlir/include/mlir/TableGen/Dialect.h
index 99217d8..5e85806 100644
--- a/mlir/include/mlir/TableGen/Dialect.h
+++ b/mlir/include/mlir/TableGen/Dialect.h
@@ -14,7 +14,6 @@
 
 #include "mlir/Support/LLVM.h"
 #include <string>
-#include <vector>
 
 namespace llvm {
 class Record;
@@ -26,7 +25,7 @@ namespace tblgen {
 // and provides helper methods for accessing them.
 class Dialect {
 public:
-  explicit Dialect(const llvm::Record *def);
+  explicit Dialect(const llvm::Record *def) : def(def) {}
 
   // Returns the name of this dialect.
   StringRef getName() const;
@@ -44,10 +43,6 @@ public:
   // Returns the description of the dialect. Returns empty string if none.
   StringRef getDescription() const;
 
-  // Returns the list of dialect (class names) that this dialect depends on.
-  // These are dialects that will be loaded on construction of this dialect.
-  ArrayRef<StringRef> getDependentDialects() const;
-
   // Returns the dialects extra class declaration code.
   llvm::Optional<StringRef> getExtraClassDeclaration() const;
 
@@ -75,7 +70,6 @@ public:
 
 private:
   const llvm::Record *def;
-  std::vector<StringRef> dependentDialects;
 };
 } // end namespace tblgen
 } // end namespace mlir
diff --git a/mlir/include/mlir/TableGen/Pass.h b/mlir/include/mlir/TableGen/Pass.h
index 968c854..02427e4 100644
--- a/mlir/include/mlir/TableGen/Pass.h
+++ b/mlir/include/mlir/TableGen/Pass.h
@@ -94,9 +94,6 @@ public:
   /// Return the C++ constructor call to create an instance of this pass.
   StringRef getConstructor() const;
 
-  /// Return the dialects this pass needs to be registered.
-  ArrayRef<StringRef> getDependentDialects() const;
-
   /// Return the options provided by this pass.
   ArrayRef<PassOption> getOptions() const;
 
@@ -107,7 +104,6 @@ public:
 
 private:
   const llvm::Record *def;
-  std::vector<StringRef> dependentDialects;
   std::vector<PassOption> options;
   std::vector<PassStatistic> statistics;
 };
diff --git a/mlir/include/mlir/Transforms/Passes.td b/mlir/include/mlir/Transforms/Passes.td
index 3292d5e..7787805 100644
--- a/mlir/include/mlir/Transforms/Passes.td
+++ b/mlir/include/mlir/Transforms/Passes.td
@@ -162,8 +162,6 @@ def BufferPlacement : FunctionPass<"buffer-placement"> {
 
   }];
   let constructor = "mlir::createBufferPlacementPass()";
-  // TODO: this pass likely shouldn't depend on Linalg?
-  let dependentDialects = ["linalg::LinalgDialect"];
 }
 
 def Canonicalizer : Pass<"canonicalize"> {
diff --git a/mlir/lib/CAPI/IR/IR.cpp b/mlir/lib/CAPI/IR/IR.cpp
index 1cb2ce5..4ccfb45 100644
--- a/mlir/lib/CAPI/IR/IR.cpp
+++ b/mlir/lib/CAPI/IR/IR.cpp
@@ -9,7 +9,6 @@
 #include "mlir-c/IR.h"
 
 #include "mlir/IR/Attributes.h"
-#include "mlir/IR/Dialect.h"
 #include "mlir/IR/Module.h"
 #include "mlir/IR/Operation.h"
 #include "mlir/IR/Types.h"
@@ -90,16 +89,12 @@ private:
 /* ========================================================================== */
 
 MlirContext mlirContextCreate() {
-  auto *context = new MLIRContext(false);
+  auto *context = new MLIRContext;
   return wrap(context);
 }
 
 void mlirContextDestroy(MlirContext context) { delete unwrap(context); }
 
-void mlirContextLoadAllDialects(MlirContext context) {
-  unwrap(context)->loadAllGloballyRegisteredDialects();
-}
-
 /* ========================================================================== */
 /* Location API.                                                              */
 /* ========================================================================== */
diff --git a/mlir/lib/Conversion/GPUToVulkan/ConvertGPULaunchFuncToVulkanLaunchFunc.cpp b/mlir/lib/Conversion/GPUToVulkan/ConvertGPULaunchFuncToVulkanLaunchFunc.cpp
index 4267393..1ebf481 100644
--- a/mlir/lib/Conversion/GPUToVulkan/ConvertGPULaunchFuncToVulkanLaunchFunc.cpp
+++ b/mlir/lib/Conversion/GPUToVulkan/ConvertGPULaunchFuncToVulkanLaunchFunc.cpp
@@ -16,7 +16,6 @@
 #include "../PassDetail.h"
 #include "mlir/Conversion/GPUToVulkan/ConvertGPUToVulkanPass.h"
 #include "mlir/Dialect/GPU/GPUDialect.h"
-#include "mlir/Dialect/SPIRV/SPIRVDialect.h"
 #include "mlir/Dialect/SPIRV/SPIRVOps.h"
 #include "mlir/Dialect/SPIRV/Serialization.h"
 #include "mlir/Dialect/StandardOps/IR/Ops.h"
diff --git a/mlir/lib/Conversion/LinalgToLLVM/LinalgToLLVM.cpp b/mlir/lib/Conversion/LinalgToLLVM/LinalgToLLVM.cpp
index 0460d98..7b57854 100644
--- a/mlir/lib/Conversion/LinalgToLLVM/LinalgToLLVM.cpp
+++ b/mlir/lib/Conversion/LinalgToLLVM/LinalgToLLVM.cpp
@@ -19,7 +19,6 @@
 #include "mlir/Dialect/Linalg/IR/LinalgOps.h"
 #include "mlir/Dialect/Linalg/IR/LinalgTypes.h"
 #include "mlir/Dialect/Linalg/Passes.h"
-#include "mlir/Dialect/SCF/SCF.h"
 #include "mlir/Dialect/StandardOps/EDSC/Intrinsics.h"
 #include "mlir/IR/AffineExpr.h"
 #include "mlir/IR/AffineMap.h"
diff --git a/mlir/lib/Conversion/PassDetail.h b/mlir/lib/Conversion/PassDetail.h
index 7fa5a5a..6da0bc8 100644
--- a/mlir/lib/Conversion/PassDetail.h
+++ b/mlir/lib/Conversion/PassDetail.h
@@ -12,43 +12,11 @@
 #include "mlir/Pass/Pass.h"
 
 namespace mlir {
-class AffineDialect;
-class StandardOpsDialect;
-
-// Forward declaration from Dialect.h
-template <typename ConcreteDialect>
-void registerDialect(DialectRegistry &registry);
 
 namespace gpu {
-class GPUDialect;
 class GPUModuleOp;
 } // end namespace gpu
 
-namespace LLVM {
-class LLVMDialect;
-class LLVMAVX512Dialect;
-} // end namespace LLVM
-
-namespace NVVM {
-class NVVMDialect;
-} // end namespace NVVM
-
-namespace ROCDL {
-class ROCDLDialect;
-} // end namespace ROCDL
-
-namespace scf {
-class SCFDialect;
-} // end namespace scf
-
-namespace spirv {
-class SPIRVDialect;
-} // end namespace spirv
-
-namespace vector {
-class VectorDialect;
-} // end namespace vector
-
 #define GEN_PASS_CLASSES
 #include "mlir/Conversion/Passes.h.inc"
 
diff --git a/mlir/lib/Conversion/StandardToLLVM/StandardToLLVM.cpp b/mlir/lib/Conversion/StandardToLLVM/StandardToLLVM.cpp
index 6096703..efe4a3c 100644
--- a/mlir/lib/Conversion/StandardToLLVM/StandardToLLVM.cpp
+++ b/mlir/lib/Conversion/StandardToLLVM/StandardToLLVM.cpp
@@ -125,7 +125,7 @@ LLVMTypeConverter::LLVMTypeConverter(MLIRContext *ctx)
 /// Create an LLVMTypeConverter using custom LowerToLLVMOptions.
 LLVMTypeConverter::LLVMTypeConverter(MLIRContext *ctx,
                                      const LowerToLLVMOptions &options)
-    : llvmDialect(ctx->getOrLoadDialect<LLVM::LLVMDialect>()),
+    : llvmDialect(ctx->getRegisteredDialect<LLVM::LLVMDialect>()),
       options(options) {
   assert(llvmDialect && "LLVM IR dialect is not registered");
   if (options.indexBitwidth == kDeriveIndexBitwidthFromDataLayout)
diff --git a/mlir/lib/Conversion/StandardToSPIRV/LegalizeStandardForSPIRV.cpp b/mlir/lib/Conversion/StandardToSPIRV/LegalizeStandardForSPIRV.cpp
index a2e608d..19643d2 100644
--- a/mlir/lib/Conversion/StandardToSPIRV/LegalizeStandardForSPIRV.cpp
+++ b/mlir/lib/Conversion/StandardToSPIRV/LegalizeStandardForSPIRV.cpp
@@ -14,7 +14,6 @@
 #include "../PassDetail.h"
 #include "mlir/Conversion/StandardToSPIRV/ConvertStandardToSPIRV.h"
 #include "mlir/Conversion/StandardToSPIRV/ConvertStandardToSPIRVPass.h"
-#include "mlir/Dialect/SPIRV/SPIRVDialect.h"
 #include "mlir/Dialect/StandardOps/IR/Ops.h"
 #include "mlir/Dialect/Vector/VectorOps.h"
 #include "mlir/IR/PatternMatch.h"
diff --git a/mlir/lib/Dialect/Affine/Transforms/PassDetail.h b/mlir/lib/Dialect/Affine/Transforms/PassDetail.h
index da8f7ac..3bae059 100644
--- a/mlir/lib/Dialect/Affine/Transforms/PassDetail.h
+++ b/mlir/lib/Dialect/Affine/Transforms/PassDetail.h
@@ -12,16 +12,6 @@
 #include "mlir/Pass/Pass.h"
 
 namespace mlir {
-// Forward declaration from Dialect.h
-template <typename ConcreteDialect>
-void registerDialect(DialectRegistry &registry);
-
-namespace linalg {
-class LinalgDialect;
-} // end namespace linalg
-namespace vector {
-class VectorDialect;
-} // end namespace vector
 
 #define GEN_PASS_CLASSES
 #include "mlir/Dialect/Affine/Passes.h.inc"
diff --git a/mlir/lib/Dialect/Linalg/IR/LinalgOps.cpp b/mlir/lib/Dialect/Linalg/IR/LinalgOps.cpp
index bf18c6c..009699b 100644
--- a/mlir/lib/Dialect/Linalg/IR/LinalgOps.cpp
+++ b/mlir/lib/Dialect/Linalg/IR/LinalgOps.cpp
@@ -1224,7 +1224,6 @@ template <typename NamedStructuredOpType>
 static ParseResult parseNamedStructuredOp(OpAsmParser &parser,
                                           OperationState &result) {
   SmallVector<OpAsmParser::OperandType, 8> operandsInfo;
-  result.getContext()->getOrLoadDialect<StandardOpsDialect>();
 
   // Optional attributes may be added.
   if (parser.parseOperandList(operandsInfo) ||
diff --git a/mlir/lib/Dialect/Linalg/Transforms/PassDetail.h b/mlir/lib/Dialect/Linalg/Transforms/PassDetail.h
index 0415aeb..7fa05ff 100644
--- a/mlir/lib/Dialect/Linalg/Transforms/PassDetail.h
+++ b/mlir/lib/Dialect/Linalg/Transforms/PassDetail.h
@@ -9,18 +9,9 @@
 #ifndef DIALECT_LINALG_TRANSFORMS_PASSDETAIL_H_
 #define DIALECT_LINALG_TRANSFORMS_PASSDETAIL_H_
 
-#include "mlir/Dialect/Affine/IR/AffineOps.h"
-#include "mlir/IR/Dialect.h"
 #include "mlir/Pass/Pass.h"
 
 namespace mlir {
-// Forward declaration from Dialect.h
-template <typename ConcreteDialect>
-void registerDialect(DialectRegistry &registry);
-
-namespace scf {
-class SCFDialect;
-} // end namespace scf
 
 #define GEN_PASS_CLASSES
 #include "mlir/Dialect/Linalg/Passes.h.inc"
diff --git a/mlir/lib/Dialect/SCF/Transforms/PassDetail.h b/mlir/lib/Dialect/SCF/Transforms/PassDetail.h
index 6fa7f22..95f8636 100644
--- a/mlir/lib/Dialect/SCF/Transforms/PassDetail.h
+++ b/mlir/lib/Dialect/SCF/Transforms/PassDetail.h
@@ -12,11 +12,6 @@
 #include "mlir/Pass/Pass.h"
 
 namespace mlir {
-// Forward declaration from Dialect.h
-template <typename ConcreteDialect>
-void registerDialect(DialectRegistry &registry);
-
-class AffineDialect;
 
 #define GEN_PASS_CLASSES
 #include "mlir/Dialect/SCF/Passes.h.inc"
diff --git a/mlir/lib/Dialect/SDBM/SDBMExpr.cpp b/mlir/lib/Dialect/SDBM/SDBMExpr.cpp
index a1971c3..435c7fe 100644
--- a/mlir/lib/Dialect/SDBM/SDBMExpr.cpp
+++ b/mlir/lib/Dialect/SDBM/SDBMExpr.cpp
@@ -517,7 +517,7 @@ Optional<SDBMExpr> SDBMExpr::tryConvertAffineExpr(AffineExpr affine) {
 
     SDBMDialect *dialect;
   } converter;
-  converter.dialect = affine.getContext()->getOrLoadDialect<SDBMDialect>();
+  converter.dialect = affine.getContext()->getRegisteredDialect<SDBMDialect>();
 
   if (auto result = converter.visit(affine))
     return result;
diff --git a/mlir/lib/ExecutionEngine/JitRunner.cpp b/mlir/lib/ExecutionEngine/JitRunner.cpp
index 2b18adb..7959183 100644
--- a/mlir/lib/ExecutionEngine/JitRunner.cpp
+++ b/mlir/lib/ExecutionEngine/JitRunner.cpp
@@ -259,9 +259,7 @@ int mlir::JitRunnerMain(
     }
   }
 
-  MLIRContext context(/*loadAllDialects=*/false);
-  registerAllDialects(&context);
-
+  MLIRContext context;
   auto m = parseMLIRInput(options.inputFilename, &context);
   if (!m) {
     llvm::errs() << "could not parse the input IR\n";
diff --git a/mlir/lib/IR/Dialect.cpp b/mlir/lib/IR/Dialect.cpp
index cd04cfa..555bb2b 100644
--- a/mlir/lib/IR/Dialect.cpp
+++ b/mlir/lib/IR/Dialect.cpp
@@ -27,26 +27,21 @@ DialectAsmParser::~DialectAsmParser() {}
 //===----------------------------------------------------------------------===//
 
 /// Registry for all dialect allocation functions.
-static llvm::ManagedStatic<DialectRegistry> dialectRegistry;
-DialectRegistry &mlir::getGlobalDialectRegistry() { return *dialectRegistry; }
-
-Dialect *DialectRegistry::loadByName(StringRef name, MLIRContext *context) {
-  auto it = registry.find(std::string(name));
-  if (it == registry.end())
-    return nullptr;
-  return it->second.second(context);
+static llvm::ManagedStatic<llvm::MapVector<TypeID, DialectAllocatorFunction>>
+    dialectRegistry;
+
+void Dialect::registerDialectAllocator(
+    TypeID typeID, const DialectAllocatorFunction &function) {
+  assert(function &&
+         "Attempting to register an empty dialect initialize function");
+  dialectRegistry->insert({typeID, function});
 }
 
-void DialectRegistry::insert(TypeID typeID, StringRef name,
-                             DialectAllocatorFunction ctor) {
-  auto inserted =
-    registry.insert(std::make_pair((std::string)name,
-                                   std::make_pair(typeID, ctor)));
-  if (!inserted.second && inserted.first->second.first != typeID) {
-    llvm::report_fatal_error(
-        "Trying to register different dialects for the same namespace: " +
-        name);
-  }
+/// Registers all dialects and hooks from the global registries with the
+/// specified MLIRContext.
+void mlir::registerAllDialects(MLIRContext *context) {
+  for (const auto &it : *dialectRegistry)
+    it.second(context);
 }
 
 //===----------------------------------------------------------------------===//
@@ -124,7 +119,7 @@ DialectInterface::~DialectInterface() {}
 
 DialectInterfaceCollectionBase::DialectInterfaceCollectionBase(
     MLIRContext *ctx, TypeID interfaceKind) {
-  for (auto *dialect : ctx->getLoadedDialects()) {
+  for (auto *dialect : ctx->getRegisteredDialects()) {
     if (auto *interface = dialect->getRegisteredInterface(interfaceKind)) {
       interfaces.insert(interface);
       orderedInterfaces.push_back(interface);
diff --git a/mlir/lib/IR/MLIRContext.cpp b/mlir/lib/IR/MLIRContext.cpp
index ed8e3db..0d66070 100644
--- a/mlir/lib/IR/MLIRContext.cpp
+++ b/mlir/lib/IR/MLIRContext.cpp
@@ -31,13 +31,10 @@
 #include "llvm/ADT/Twine.h"
 #include "llvm/Support/Allocator.h"
 #include "llvm/Support/CommandLine.h"
-#include "llvm/Support/Debug.h"
 #include "llvm/Support/RWMutex.h"
 #include "llvm/Support/raw_ostream.h"
 #include <memory>
 
-#define DEBUG_TYPE "mlircontext"
-
 using namespace mlir;
 using namespace mlir::detail;
 
@@ -278,8 +275,7 @@ public:
 
   /// This is a list of dialects that are created referring to this context.
   /// The MLIRContext owns the objects.
-  DenseMap<StringRef, std::unique_ptr<Dialect>> loadedDialects;
-  DialectRegistry dialectsRegistry;
+  std::vector<std::unique_ptr<Dialect>> dialects;
 
   /// This is a mapping from operation name to AbstractOperation for registered
   /// operations.
@@ -350,7 +346,7 @@ public:
 };
 } // end namespace mlir
 
-MLIRContext::MLIRContext(bool loadAllDialects) : impl(new MLIRContextImpl()) {
+MLIRContext::MLIRContext() : impl(new MLIRContextImpl()) {
   // Initialize values based on the command line flags if they were provided.
   if (clOptions.isConstructed()) {
     disableMultithreading(clOptions->disableThreading);
@@ -359,9 +355,8 @@ MLIRContext::MLIRContext(bool loadAllDialects) : impl(new MLIRContextImpl()) {
   }
 
   // Register dialects with this context.
-  getOrLoadDialect<BuiltinDialect>();
-  if (loadAllDialects)
-    loadAllGloballyRegisteredDialects();
+  getOrCreateDialect<BuiltinDialect>();
+  registerAllDialects(this);
 
   // Initialize several common attributes and types to avoid the need to lock
   // the context when accessing them.
@@ -443,72 +438,54 @@ DiagnosticEngine &MLIRContext::getDiagEngine() { return getImpl().diagEngine; }
 // Dialect and Operation Registration
 //===----------------------------------------------------------------------===//
 
-DialectRegistry &MLIRContext::getDialectRegistry() {
-  return impl->dialectsRegistry;
-}
-
 /// Return information about all registered IR dialects.
-std::vector<Dialect *> MLIRContext::getLoadedDialects() {
+std::vector<Dialect *> MLIRContext::getRegisteredDialects() {
   std::vector<Dialect *> result;
-  result.reserve(impl->loadedDialects.size());
-  for (auto &dialect : impl->loadedDialects) {
-    result.push_back(dialect.second.get());
-  }
-  llvm::sort(result, [](Dialect *lhs, Dialect *rhs) {
-    return lhs->getNamespace() < rhs->getNamespace();
-  });
-  return result;
-}
-std::vector<StringRef> MLIRContext::getAvailableDialects() {
-  std::vector<StringRef> result;
-  for (auto &dialect : impl->dialectsRegistry)
-    result.push_back(dialect.first);
+  result.reserve(impl->dialects.size());
+  for (auto &dialect : impl->dialects)
+    result.push_back(dialect.get());
   return result;
 }
 
 /// Get a registered IR dialect with the given namespace. If none is found,
 /// then return nullptr.
-Dialect *MLIRContext::getLoadedDialect(StringRef name) {
+Dialect *MLIRContext::getRegisteredDialect(StringRef name) {
   // Dialects are sorted by name, so we can use binary search for lookup.
-  auto it = impl->loadedDialects.find(name);
-  return (it != impl->loadedDialects.end()) ? it->second.get() : nullptr;
-}
-
-Dialect *MLIRContext::getOrLoadDialect(StringRef name) {
-  Dialect *dialect = getLoadedDialect(name);
-  if (dialect)
-    return dialect;
-  return impl->dialectsRegistry.loadByName(name, this);
+  auto it = llvm::lower_bound(
+      impl->dialects, name,
+      [](const auto &lhs, StringRef rhs) { return lhs->getNamespace() < rhs; });
+  return (it != impl->dialects.end() && (*it)->getNamespace() == name)
+             ? (*it).get()
+             : nullptr;
 }
 
 /// Get a dialect for the provided namespace and TypeID: abort the program if a
 /// dialect exist for this namespace with different TypeID. Returns a pointer to
 /// the dialect owned by the context.
 Dialect *
-MLIRContext::getOrLoadDialect(StringRef dialectNamespace, TypeID dialectID,
-                              function_ref<std::unique_ptr<Dialect>()> ctor) {
+MLIRContext::getOrCreateDialect(StringRef dialectNamespace, TypeID dialectID,
+                                function_ref<std::unique_ptr<Dialect>()> ctor) {
   auto &impl = getImpl();
   // Get the correct insertion position sorted by namespace.
-  std::unique_ptr<Dialect> &dialect = impl.loadedDialects[dialectNamespace];
-
-  if (!dialect) {
-    LLVM_DEBUG(llvm::dbgs()
-               << "Load new dialect in Context" << dialectNamespace);
-    dialect = ctor();
-    assert(dialect && "dialect ctor failed");
-    return dialect.get();
-  }
+  auto insertPt =
+      llvm::lower_bound(impl.dialects, nullptr,
+                        [&](const std::unique_ptr<Dialect> &lhs,
+                            const std::unique_ptr<Dialect> &rhs) {
+                          if (!lhs)
+                            return dialectNamespace < rhs->getNamespace();
+                          return lhs->getNamespace() < dialectNamespace;
+                        });
 
   // Abort if dialect with namespace has already been registered.
-  if (dialect->getTypeID() != dialectID)
+  if (insertPt != impl.dialects.end() &&
+      (*insertPt)->getNamespace() == dialectNamespace) {
+    if ((*insertPt)->getTypeID() == dialectID)
+      return insertPt->get();
     llvm::report_fatal_error("a dialect with namespace '" + dialectNamespace +
                              "' has already been registered");
-
-  return dialect.get();
-}
-
-void MLIRContext::loadAllGloballyRegisteredDialects() {
-  getGlobalDialectRegistry().loadAll(this);
+  }
+  auto it = impl.dialects.insert(insertPt, ctor());
+  return &**it;
 }
 
 bool MLIRContext::allowsUnregisteredDialects() {
diff --git a/mlir/lib/IR/Operation.cpp b/mlir/lib/IR/Operation.cpp
index dce570a..152ed01 100644
--- a/mlir/lib/IR/Operation.cpp
+++ b/mlir/lib/IR/Operation.cpp
@@ -214,7 +214,7 @@ Dialect *Operation::getDialect() {
 
   // If this operation hasn't been registered or doesn't have abstract
   // operation, try looking up the dialect name in the context.
-  return getContext()->getLoadedDialect(getName().getDialect());
+  return getContext()->getRegisteredDialect(getName().getDialect());
 }
 
 Region *Operation::getParentRegion() {
diff --git a/mlir/lib/IR/Verifier.cpp b/mlir/lib/IR/Verifier.cpp
index 4caf989..b1aed88 100644
--- a/mlir/lib/IR/Verifier.cpp
+++ b/mlir/lib/IR/Verifier.cpp
@@ -50,7 +50,7 @@ public:
   Dialect *getDialectForAttribute(const NamedAttribute &attr) {
     assert(attr.first.strref().contains('.') && "expected dialect attribute");
     auto dialectNamePair = attr.first.strref().split('.');
-    return ctx->getLoadedDialect(dialectNamePair.first);
+    return ctx->getRegisteredDialect(dialectNamePair.first);
   }
 
 private:
@@ -218,7 +218,7 @@ LogicalResult OperationVerifier::verifyOperation(Operation &op) {
   auto it = dialectAllowsUnknownOps.find(dialectPrefix);
   if (it == dialectAllowsUnknownOps.end()) {
     // If the operation dialect is registered, query it directly.
-    if (auto *dialect = ctx->getLoadedDialect(dialectPrefix))
+    if (auto *dialect = ctx->getRegisteredDialect(dialectPrefix))
       it = dialectAllowsUnknownOps
                .try_emplace(dialectPrefix, dialect->allowsUnknownOperations())
                .first;
diff --git a/mlir/lib/Parser/AttributeParser.cpp b/mlir/lib/Parser/AttributeParser.cpp
index 37ee938..1c1261e 100644
--- a/mlir/lib/Parser/AttributeParser.cpp
+++ b/mlir/lib/Parser/AttributeParser.cpp
@@ -12,7 +12,6 @@
 
 #include "Parser.h"
 #include "mlir/IR/AffineMap.h"
-#include "mlir/IR/Dialect.h"
 #include "mlir/IR/IntegerSet.h"
 #include "mlir/IR/StandardTypes.h"
 #include "llvm/ADT/StringExtras.h"
@@ -247,11 +246,6 @@ ParseResult Parser::parseAttributeDict(NamedAttrList &attributes) {
       return emitError("duplicate key in dictionary attribute");
     consumeToken();
 
-    // Lazy load a dialect in the context if there is a possible namespace.
-    auto splitName = nameId->strref().split('.');
-    if (!splitName.second.empty())
-      getContext()->getOrLoadDialect(splitName.first);
-
     // Try to parse the '=' for the attribute value.
     if (!consumeIf(Token::equal)) {
       // If there is no '=', we treat this as a unit attribute.
@@ -823,9 +817,7 @@ Attribute Parser::parseOpaqueElementsAttr(Type attrType) {
     return (emitError("expected dialect namespace"), nullptr);
 
   auto name = getToken().getStringValue();
-  // Lazy load a dialect in the context if there is a possible namespace.
-  Dialect *dialect = builder.getContext()->getOrLoadDialect(name);
-
+  auto *dialect = builder.getContext()->getRegisteredDialect(name);
   // TODO: Allow for having an unknown dialect on an opaque
   // attribute. Otherwise, it can't be roundtripped without having the dialect
   // registered.
diff --git a/mlir/lib/Parser/DialectSymbolParser.cpp b/mlir/lib/Parser/DialectSymbolParser.cpp
index d45ddf0..3b522a8 100644
--- a/mlir/lib/Parser/DialectSymbolParser.cpp
+++ b/mlir/lib/Parser/DialectSymbolParser.cpp
@@ -526,8 +526,7 @@ Attribute Parser::parseExtendedAttr(Type type) {
           return Attribute();
 
         // If we found a registered dialect, then ask it to parse the attribute.
-        if (Dialect *dialect =
-                builder.getContext()->getOrLoadDialect(dialectName)) {
+        if (auto *dialect = state.context->getRegisteredDialect(dialectName)) {
           return parseSymbol<Attribute>(
               symbolData, state.context, state.symbols, [&](Parser &parser) {
                 CustomDialectAsmParser customParser(symbolData, parser);
@@ -564,9 +563,7 @@ Type Parser::parseExtendedType() {
       [&](StringRef dialectName, StringRef symbolData,
           llvm::SMLoc loc) -> Type {
         // If we found a registered dialect, then ask it to parse the type.
-        auto *dialect = state.context->getOrLoadDialect(dialectName);
-
-        if (dialect) {
+        if (auto *dialect = state.context->getRegisteredDialect(dialectName)) {
           return parseSymbol<Type>(
               symbolData, state.context, state.symbols, [&](Parser &parser) {
                 CustomDialectAsmParser customParser(symbolData, parser);
diff --git a/mlir/lib/Parser/Parser.cpp b/mlir/lib/Parser/Parser.cpp
index 837b08c..3a995a4 100644
--- a/mlir/lib/Parser/Parser.cpp
+++ b/mlir/lib/Parser/Parser.cpp
@@ -12,7 +12,6 @@
 
 #include "Parser.h"
 #include "mlir/IR/AffineMap.h"
-#include "mlir/IR/Dialect.h"
 #include "mlir/IR/Module.h"
 #include "mlir/IR/Verifier.h"
 #include "mlir/Parser.h"
@@ -728,7 +727,7 @@ Operation *OperationParser::parseGenericOperation() {
   // Get location information for the operation.
   auto srcLocation = getEncodedSourceLocation(getToken().getLoc());
 
-  std::string name = getToken().getStringValue();
+  auto name = getToken().getStringValue();
   if (name.empty())
     return (emitError("empty operation name is invalid"), nullptr);
   if (name.find('\0') != StringRef::npos)
@@ -738,15 +737,6 @@ Operation *OperationParser::parseGenericOperation() {
 
   OperationState result(srcLocation, name);
 
-  // Lazy load dialects in the context as needed.
-  if (!result.name.getAbstractOperation()) {
-    StringRef dialectName = StringRef(name).split('.').first;
-    if (!getContext()->getLoadedDialect(dialectName) &&
-        getContext()->getOrLoadDialect(dialectName)) {
-      result.name = OperationName(name, getContext());
-    }
-  }
-
   // Parse the operand list.
   SmallVector<SSAUseInfo, 8> operandInfos;
   if (parseToken(Token::l_paren, "expected '(' to start operand list") ||
@@ -1452,28 +1442,17 @@ private:
 
 Operation *
 OperationParser::parseCustomOperation(ArrayRef<ResultRecord> resultIDs) {
-  llvm::SMLoc opLoc = getToken().getLoc();
-  StringRef opName = getTokenSpelling();
+  auto opLoc = getToken().getLoc();
+  auto opName = getTokenSpelling();
 
   auto *opDefinition = AbstractOperation::lookup(opName, getContext());
-  if (!opDefinition) {
-    if (opName.contains('.')) {
-      // This op has a dialect, we try to check if we can register it in the
-      // context on the fly.
-      StringRef dialectName = opName.split('.').first;
-      if (!getContext()->getLoadedDialect(dialectName) &&
-          getContext()->getOrLoadDialect(dialectName)) {
-        opDefinition = AbstractOperation::lookup(opName, getContext());
-      }
-    } else {
-      // If the operation name has no namespace prefix we treat it as a standard
-      // operation and prefix it with "std".
-      // TODO: Would it be better to just build a mapping of the registered
-      // operations in the standard dialect?
-      if (getContext()->getOrLoadDialect("std"))
-        opDefinition = AbstractOperation::lookup(Twine("std." + opName).str(),
-                                                 getContext());
-    }
+  if (!opDefinition && !opName.contains('.')) {
+    // If the operation name has no namespace prefix we treat it as a standard
+    // operation and prefix it with "std".
+    // TODO: Would it be better to just build a mapping of the registered
+    // operations in the standard dialect?
+    opDefinition =
+        AbstractOperation::lookup(Twine("std." + opName).str(), getContext());
   }
 
   if (!opDefinition) {
diff --git a/mlir/lib/Pass/Pass.cpp b/mlir/lib/Pass/Pass.cpp
index 9debd11..b791bf4 100644
--- a/mlir/lib/Pass/Pass.cpp
+++ b/mlir/lib/Pass/Pass.cpp
@@ -290,13 +290,6 @@ OpPassManager::pass_iterator OpPassManager::begin() {
 }
 OpPassManager::pass_iterator OpPassManager::end() { return impl->passes.end(); }
 
-OpPassManager::const_pass_iterator OpPassManager::begin() const {
-  return impl->passes.begin();
-}
-OpPassManager::const_pass_iterator OpPassManager::end() const {
-  return impl->passes.end();
-}
-
 /// Run all of the passes in this manager over the current operation.
 LogicalResult OpPassManager::run(Operation *op, AnalysisManager am) {
   // Run each of the held passes.
@@ -353,16 +346,6 @@ void OpPassManager::printAsTextualPipeline(raw_ostream &os) {
   ::printAsTextualPipeline(impl->passes, os);
 }
 
-static void registerDialectsForPipeline(const OpPassManager &pm,
-                                        DialectRegistry &dialects) {
-  for (const Pass &pass : pm.getPasses())
-    pass.getDependentDialects(dialects);
-}
-
-void OpPassManager::getDependentDialects(DialectRegistry &dialects) const {
-  registerDialectsForPipeline(*this, dialects);
-}
-
 //===----------------------------------------------------------------------===//
 // OpToOpPassAdaptor
 //===----------------------------------------------------------------------===//
@@ -395,11 +378,6 @@ OpToOpPassAdaptor::OpToOpPassAdaptor(OpPassManager &&mgr) {
   mgrs.emplace_back(std::move(mgr));
 }
 
-void OpToOpPassAdaptor::getDependentDialects(DialectRegistry &dialects) const {
-  for (auto &pm : mgrs)
-    pm.getDependentDialects(dialects);
-}
-
 /// Merge the current pass adaptor into given 'rhs'.
 void OpToOpPassAdaptor::mergeInto(OpToOpPassAdaptor &rhs) {
   for (auto &pm : mgrs) {
@@ -743,11 +721,6 @@ LogicalResult PassManager::run(ModuleOp module) {
   // pipeline.
   getImpl().coalesceAdjacentAdaptorPasses();
 
-  // Register all dialects for the current pipeline.
-  DialectRegistry dependent_dialects;
-  getDependentDialects(dependent_dialects);
-  dependent_dialects.loadAll(module.getContext());
-
   // Construct an analysis manager for the pipeline.
   ModuleAnalysisManager am(module, instrumentor.get());
 
diff --git a/mlir/lib/Pass/PassDetail.h b/mlir/lib/Pass/PassDetail.h
index f69701d..2342a1a 100644
--- a/mlir/lib/Pass/PassDetail.h
+++ b/mlir/lib/Pass/PassDetail.h
@@ -43,10 +43,6 @@ public:
   /// Returns the pass managers held by this adaptor.
   MutableArrayRef<OpPassManager> getPassManagers() { return mgrs; }
 
-  /// Populate the set of dependent dialects for the passes in the current
-  /// adaptor.
-  void getDependentDialects(DialectRegistry &dialects) const override;
-
   /// Return the async pass managers held by this parallel adaptor.
   MutableArrayRef<SmallVector<OpPassManager, 1>> getParallelPassManagers() {
     return asyncExecutors;
diff --git a/mlir/lib/Support/MlirOptMain.cpp b/mlir/lib/Support/MlirOptMain.cpp
index e450fb3..25e1970 100644
--- a/mlir/lib/Support/MlirOptMain.cpp
+++ b/mlir/lib/Support/MlirOptMain.cpp
@@ -75,17 +75,13 @@ static LogicalResult processBuffer(raw_ostream &os,
                                    std::unique_ptr<MemoryBuffer> ownedBuffer,
                                    bool verifyDiagnostics, bool verifyPasses,
                                    bool allowUnregisteredDialects,
-                                   bool preloadDialectsInContext,
                                    const PassPipelineCLParser &passPipeline) {
   // Tell sourceMgr about this buffer, which is what the parser will pick up.
   SourceMgr sourceMgr;
   sourceMgr.AddNewSourceBuffer(std::move(ownedBuffer), SMLoc());
 
   // Parse the input file.
-  MLIRContext context(/*loadAllDialects=*/false);
-  registerAllDialects(&context);
-  if (preloadDialectsInContext)
-    context.getDialectRegistry().loadAll(&context);
+  MLIRContext context;
   context.allowUnregisteredDialects(allowUnregisteredDialects);
   context.printOpOnDiagnostic(!verifyDiagnostics);
 
@@ -115,8 +111,7 @@ LogicalResult mlir::MlirOptMain(raw_ostream &os,
                                 const PassPipelineCLParser &passPipeline,
                                 bool splitInputFile, bool verifyDiagnostics,
                                 bool verifyPasses,
-                                bool allowUnregisteredDialects,
-                                bool preloadDialectsInContext) {
+                                bool allowUnregisteredDialects) {
   // The split-input-file mode is a very specific mode that slices the file
   // up into small pieces and checks each independently.
   if (splitInputFile)
@@ -125,11 +120,10 @@ LogicalResult mlir::MlirOptMain(raw_ostream &os,
         [&](std::unique_ptr<MemoryBuffer> chunkBuffer, raw_ostream &os) {
           return processBuffer(os, std::move(chunkBuffer), verifyDiagnostics,
                                verifyPasses, allowUnregisteredDialects,
-                               preloadDialectsInContext, passPipeline);
+                               passPipeline);
         },
         os);
 
   return processBuffer(os, std::move(buffer), verifyDiagnostics, verifyPasses,
-                       allowUnregisteredDialects, preloadDialectsInContext,
-                       passPipeline);
+                       allowUnregisteredDialects, passPipeline);
 }
diff --git a/mlir/lib/TableGen/Dialect.cpp b/mlir/lib/TableGen/Dialect.cpp
index 8aee067..6af77e7 100644
--- a/mlir/lib/TableGen/Dialect.cpp
+++ b/mlir/lib/TableGen/Dialect.cpp
@@ -16,11 +16,6 @@
 using namespace mlir;
 using namespace mlir::tblgen;
 
-Dialect::Dialect(const llvm::Record *def) : def(def) {
-  for (StringRef dialect : def->getValueAsListOfStrings("dependentDialects"))
-    dependentDialects.push_back(dialect);
-}
-
 StringRef Dialect::getName() const { return def->getValueAsString("name"); }
 
 StringRef Dialect::getCppNamespace() const {
@@ -51,10 +46,6 @@ StringRef Dialect::getDescription() const {
   return getAsStringOrEmpty(*def, "description");
 }
 
-ArrayRef<StringRef> Dialect::getDependentDialects() const {
-  return dependentDialects;
-}
-
 llvm::Optional<StringRef> Dialect::getExtraClassDeclaration() const {
   auto value = def->getValueAsString("extraClassDeclaration");
   return value.empty() ? llvm::Optional<StringRef>() : value;
diff --git a/mlir/lib/TableGen/Pass.cpp b/mlir/lib/TableGen/Pass.cpp
index f961806..4bc46b6 100644
--- a/mlir/lib/TableGen/Pass.cpp
+++ b/mlir/lib/TableGen/Pass.cpp
@@ -69,8 +69,6 @@ Pass::Pass(const llvm::Record *def) : def(def) {
     options.push_back(PassOption(init));
   for (auto *init : def->getValueAsListOfDefs("statistics"))
     statistics.push_back(PassStatistic(init));
-  for (StringRef dialect : def->getValueAsListOfStrings("dependentDialects"))
-    dependentDialects.push_back(dialect);
 }
 
 StringRef Pass::getArgument() const {
@@ -90,9 +88,6 @@ StringRef Pass::getDescription() const {
 StringRef Pass::getConstructor() const {
   return def->getValueAsString("constructor");
 }
-ArrayRef<StringRef> Pass::getDependentDialects() const {
-  return dependentDialects;
-}
 
 ArrayRef<PassOption> Pass::getOptions() const { return options; }
 
diff --git a/mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp b/mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp
index 1d01569..470044b 100644
--- a/mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp
+++ b/mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp
@@ -836,7 +836,6 @@ LogicalResult Importer::processBasicBlock(llvm::BasicBlock *bb, Block *block) {
 OwningModuleRef
 mlir::translateLLVMIRToModule(std::unique_ptr<llvm::Module> llvmModule,
                               MLIRContext *context) {
-  context->getOrLoadDialect<LLVMDialect>();
   OwningModuleRef module(ModuleOp::create(
       FileLineColLoc::get("", /*line=*/0, /*column=*/0, context)));
 
diff --git a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
index 027422b..215c191 100644
--- a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
@@ -302,7 +302,8 @@ ModuleTranslation::ModuleTranslation(Operation *module,
     : mlirModule(module), llvmModule(std::move(llvmModule)),
       debugTranslation(
           std::make_unique<DebugTranslation>(module, *this->llvmModule)),
-      ompDialect(module->getContext()->getOrLoadDialect<omp::OpenMPDialect>()),
+      ompDialect(
+          module->getContext()->getRegisteredDialect<omp::OpenMPDialect>()),
       typeTranslator(this->llvmModule->getContext()) {
   assert(satisfiesLLVMModule(mlirModule) &&
          "mlirModule should honor LLVM's module semantics.");
@@ -943,7 +944,7 @@ ModuleTranslation::lookupValues(ValueRange values) {
 
 std::unique_ptr<llvm::Module> ModuleTranslation::prepareLLVMModule(
     Operation *m, llvm::LLVMContext &llvmContext, StringRef name) {
-  auto *dialect = m->getContext()->getOrLoadDialect<LLVM::LLVMDialect>();
+  auto *dialect = m->getContext()->getRegisteredDialect<LLVM::LLVMDialect>();
   assert(dialect && "LLVM dialect must be registered");
 
   auto llvmModule = std::make_unique<llvm::Module>(name, llvmContext);
diff --git a/mlir/lib/Transforms/PassDetail.h b/mlir/lib/Transforms/PassDetail.h
index 220ed1a..c6f7e22 100644
--- a/mlir/lib/Transforms/PassDetail.h
+++ b/mlir/lib/Transforms/PassDetail.h
@@ -12,13 +12,6 @@
 #include "mlir/Pass/Pass.h"
 
 namespace mlir {
-// Forward declaration from Dialect.h
-template <typename ConcreteDialect>
-void registerDialect(DialectRegistry &registry);
-
-namespace linalg {
-class LinalgDialect;
-} // end namespace linalg
 
 #define GEN_PASS_CLASSES
 #include "mlir/Transforms/Passes.h.inc"
diff --git a/mlir/test/CAPI/ir.c b/mlir/test/CAPI/ir.c
index df2d32f..d6ab351 100644
--- a/mlir/test/CAPI/ir.c
+++ b/mlir/test/CAPI/ir.c
@@ -243,7 +243,6 @@ static void printFirstOfEach(MlirOperation operation) {
 int main() {
   mlirRegisterAllDialects();
   MlirContext ctx = mlirContextCreate();
-  mlirContextLoadAllDialects(ctx);
   MlirLocation location = mlirLocationUnknownGet(ctx);
 
   MlirModule moduleOp = makeAdd(ctx, location);
diff --git a/mlir/test/EDSC/builder-api-test.cpp b/mlir/test/EDSC/builder-api-test.cpp
index e5766f0..3fcfcf2 100644
--- a/mlir/test/EDSC/builder-api-test.cpp
+++ b/mlir/test/EDSC/builder-api-test.cpp
@@ -36,16 +36,16 @@ using namespace mlir::edsc;
 using namespace mlir::edsc::intrinsics;
 
 static MLIRContext &globalContext() {
-  static thread_local MLIRContext context(/*loadAllDialects=*/false);
-  static thread_local bool init_once = [&]() {
-    context.getOrLoadDialect<AffineDialect>();
-    context.getOrLoadDialect<scf::SCFDialect>();
-    context.getOrLoadDialect<linalg::LinalgDialect>();
-    context.getOrLoadDialect<StandardOpsDialect>();
-    context.getOrLoadDialect<vector::VectorDialect>();
+  static bool init_once = []() {
+    registerDialect<AffineDialect>();
+    registerDialect<linalg::LinalgDialect>();
+    registerDialect<scf::SCFDialect>();
+    registerDialect<StandardOpsDialect>();
+    registerDialect<vector::VectorDialect>();
     return true;
   }();
   (void)init_once;
+  static thread_local MLIRContext context;
   context.allowUnregisteredDialects();
   return context;
 }
diff --git a/mlir/test/SDBM/sdbm-api-test.cpp b/mlir/test/SDBM/sdbm-api-test.cpp
index ddefc52..0b58e29 100644
--- a/mlir/test/SDBM/sdbm-api-test.cpp
+++ b/mlir/test/SDBM/sdbm-api-test.cpp
@@ -19,19 +19,18 @@
 
 using namespace mlir;
 
+// Load the SDBM dialect
+static DialectRegistration<SDBMDialect> SDBMRegistration;
 
 static MLIRContext *ctx() {
-  static thread_local MLIRContext context(/*loadAllDialects=*/false);
-  static thread_local bool once =
-      (context.getOrLoadDialect<SDBMDialect>(), true);
-  (void)once;
+  static thread_local MLIRContext context;
   return &context;
 }
 
 static SDBMDialect *dialect() {
   static thread_local SDBMDialect *d = nullptr;
   if (!d) {
-    d = ctx()->getOrLoadDialect<SDBMDialect>();
+    d = ctx()->getRegisteredDialect<SDBMDialect>();
   }
   return d;
 }
diff --git a/mlir/test/lib/Dialect/Affine/TestVectorizationUtils.cpp b/mlir/test/lib/Dialect/Affine/TestVectorizationUtils.cpp
index cfac2dc..a6719b0 100644
--- a/mlir/test/lib/Dialect/Affine/TestVectorizationUtils.cpp
+++ b/mlir/test/lib/Dialect/Affine/TestVectorizationUtils.cpp
@@ -14,7 +14,6 @@
 #include "mlir/Analysis/NestedMatcher.h"
 #include "mlir/Analysis/SliceAnalysis.h"
 #include "mlir/Dialect/Affine/IR/AffineOps.h"
-#include "mlir/Dialect/Vector/VectorOps.h"
 #include "mlir/Dialect/Vector/VectorUtils.h"
 #include "mlir/IR/Builders.h"
 #include "mlir/IR/Diagnostics.h"
@@ -73,9 +72,6 @@ struct VectorizerTestPass
     : public PassWrapper<VectorizerTestPass, FunctionPass> {
   static constexpr auto kTestAffineMapOpName = "test_affine_map";
   static constexpr auto kTestAffineMapAttrName = "affine_map";
-  void getDependentDialects(DialectRegistry &registry) const override {
-    registry.insert<vector::VectorDialect>();
-  }
 
   void runOnFunction() override;
   void testVectorShapeRatio(llvm::raw_ostream &outs);
diff --git a/mlir/test/lib/Dialect/SPIRV/TestAvailability.cpp b/mlir/test/lib/Dialect/SPIRV/TestAvailability.cpp
index 03c425d..0c1069f 100644
--- a/mlir/test/lib/Dialect/SPIRV/TestAvailability.cpp
+++ b/mlir/test/lib/Dialect/SPIRV/TestAvailability.cpp
@@ -30,7 +30,7 @@ void PrintOpAvailability::runOnFunction() {
   auto f = getFunction();
   llvm::outs() << f.getName() << "\n";
 
-  Dialect *spvDialect = getContext().getLoadedDialect("spv");
+  Dialect *spvDialect = getContext().getRegisteredDialect("spv");
 
   f.getOperation()->walk([&](Operation *op) {
     if (op->getDialect() != spvDialect)
diff --git a/mlir/test/lib/Dialect/Test/TestPatterns.cpp b/mlir/test/lib/Dialect/Test/TestPatterns.cpp
index be5d799..f2a17a9 100644
--- a/mlir/test/lib/Dialect/Test/TestPatterns.cpp
+++ b/mlir/test/lib/Dialect/Test/TestPatterns.cpp
@@ -768,10 +768,6 @@ struct TestTypeConversionProducer
 
 struct TestTypeConversionDriver
     : public PassWrapper<TestTypeConversionDriver, OperationPass<ModuleOp>> {
-  void getDependentDialects(DialectRegistry &registry) const override {
-    registry.insert<TestDialect>();
-  }
-
   void runOnOperation() override {
     // Initialize the type converter.
     TypeConverter converter;
diff --git a/mlir/test/lib/Transforms/TestAllReduceLowering.cpp b/mlir/test/lib/Transforms/TestAllReduceLowering.cpp
index 0c72b6c..c043d0f 100644
--- a/mlir/test/lib/Transforms/TestAllReduceLowering.cpp
+++ b/mlir/test/lib/Transforms/TestAllReduceLowering.cpp
@@ -11,7 +11,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "mlir/Dialect/GPU/Passes.h"
-#include "mlir/Dialect/StandardOps/IR/Ops.h"
 #include "mlir/IR/PatternMatch.h"
 #include "mlir/Pass/Pass.h"
 
@@ -20,9 +19,6 @@ using namespace mlir;
 namespace {
 struct TestAllReduceLoweringPass
     : public PassWrapper<TestAllReduceLoweringPass, OperationPass<ModuleOp>> {
-  void getDependentDialects(DialectRegistry &registry) const override {
-    registry.insert<StandardOpsDialect>();
-  }
   void runOnOperation() override {
     OwningRewritePatternList patterns;
     populateGpuRewritePatterns(&getContext(), patterns);
diff --git a/mlir/test/lib/Transforms/TestBufferPlacement.cpp b/mlir/test/lib/Transforms/TestBufferPlacement.cpp
index 6cc0924..5ad441a 100644
--- a/mlir/test/lib/Transforms/TestBufferPlacement.cpp
+++ b/mlir/test/lib/Transforms/TestBufferPlacement.cpp
@@ -116,10 +116,6 @@ struct TestBufferPlacementPreparationPass
     patterns->insert<GenericOpConverter>(context, placer, converter);
   }
 
-  void getDependentDialects(DialectRegistry &registry) const override {
-    registry.insert<linalg::LinalgDialect>();
-  }
-
   void runOnOperation() override {
     MLIRContext &context = this->getContext();
     ConversionTarget target(context);
diff --git a/mlir/test/lib/Transforms/TestGpuMemoryPromotion.cpp b/mlir/test/lib/Transforms/TestGpuMemoryPromotion.cpp
index 339ec1a..08862dd 100644
--- a/mlir/test/lib/Transforms/TestGpuMemoryPromotion.cpp
+++ b/mlir/test/lib/Transforms/TestGpuMemoryPromotion.cpp
@@ -13,9 +13,6 @@
 
 #include "mlir/Dialect/GPU/GPUDialect.h"
 #include "mlir/Dialect/GPU/MemoryPromotion.h"
-#include "mlir/Dialect/SCF/SCF.h"
-#include "mlir/Dialect/SPIRV/SPIRVDialect.h"
-#include "mlir/Dialect/StandardOps/IR/Ops.h"
 #include "mlir/IR/Attributes.h"
 #include "mlir/Pass/Pass.h"
 
@@ -29,11 +26,6 @@ namespace {
 class TestGpuMemoryPromotionPass
     : public PassWrapper<TestGpuMemoryPromotionPass,
                          OperationPass<gpu::GPUFuncOp>> {
-  void getDependentDialects(DialectRegistry &registry) const override {
-    registry.insert<StandardOpsDialect>();
-    registry.insert<scf::SCFDialect>();
-  }
-
   void runOnOperation() override {
     gpu::GPUFuncOp op = getOperation();
     for (unsigned i = 0, e = op.getNumArguments(); i < e; ++i) {
diff --git a/mlir/test/lib/Transforms/TestLinalgHoisting.cpp b/mlir/test/lib/Transforms/TestLinalgHoisting.cpp
index 5d4031f..d1e478f 100644
--- a/mlir/test/lib/Transforms/TestLinalgHoisting.cpp
+++ b/mlir/test/lib/Transforms/TestLinalgHoisting.cpp
@@ -10,7 +10,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "mlir/Dialect/Affine/IR/AffineOps.h"
 #include "mlir/Dialect/Linalg/IR/LinalgOps.h"
 #include "mlir/Dialect/Linalg/Transforms/Hoisting.h"
 #include "mlir/Pass/Pass.h"
@@ -23,9 +22,6 @@ struct TestLinalgHoisting
     : public PassWrapper<TestLinalgHoisting, FunctionPass> {
   TestLinalgHoisting() = default;
   TestLinalgHoisting(const TestLinalgHoisting &pass) {}
-  void getDependentDialects(DialectRegistry &registry) const override {
-    registry.insert<AffineDialect>();
-  }
 
   void runOnFunction() override;
 
diff --git a/mlir/test/lib/Transforms/TestLinalgTransforms.cpp b/mlir/test/lib/Transforms/TestLinalgTransforms.cpp
index b6f3cb4e..f6c1160 100644
--- a/mlir/test/lib/Transforms/TestLinalgTransforms.cpp
+++ b/mlir/test/lib/Transforms/TestLinalgTransforms.cpp
@@ -15,7 +15,6 @@
 #include "mlir/Dialect/Linalg/IR/LinalgOps.h"
 #include "mlir/Dialect/Linalg/Transforms/Transforms.h"
 #include "mlir/Dialect/Linalg/Utils/Utils.h"
-#include "mlir/Dialect/StandardOps/IR/Ops.h"
 #include "mlir/Dialect/Vector/VectorOps.h"
 #include "mlir/IR/PatternMatch.h"
 #include "mlir/Pass/Pass.h"
@@ -31,14 +30,6 @@ struct TestLinalgTransforms
   TestLinalgTransforms() = default;
   TestLinalgTransforms(const TestLinalgTransforms &pass) {}
 
-  void getDependentDialects(DialectRegistry &registry) const override {
-    registry.insert<AffineDialect>();
-    registry.insert<scf::SCFDialect>();
-    registry.insert<StandardOpsDialect>();
-    registry.insert<vector::VectorDialect>();
-    registry.insert<gpu::GPUDialect>();
-  }
-
   void runOnFunction() override;
 
   Option<bool> testPatterns{*this, "test-patterns",
diff --git a/mlir/test/lib/Transforms/TestVectorTransforms.cpp b/mlir/test/lib/Transforms/TestVectorTransforms.cpp
index 24e7a8c..9da3156 100644
--- a/mlir/test/lib/Transforms/TestVectorTransforms.cpp
+++ b/mlir/test/lib/Transforms/TestVectorTransforms.cpp
@@ -8,9 +8,6 @@
 
 #include <type_traits>
 
-#include "mlir/Dialect/Affine/IR/AffineOps.h"
-#include "mlir/Dialect/Linalg/IR/LinalgOps.h"
-#include "mlir/Dialect/SCF/SCF.h"
 #include "mlir/Dialect/StandardOps/IR/Ops.h"
 #include "mlir/Dialect/Vector/VectorOps.h"
 #include "mlir/Dialect/Vector/VectorTransforms.h"
@@ -131,13 +128,6 @@ struct TestVectorTransferFullPartialSplitPatterns
   TestVectorTransferFullPartialSplitPatterns() = default;
   TestVectorTransferFullPartialSplitPatterns(
       const TestVectorTransferFullPartialSplitPatterns &pass) {}
-
-  void getDependentDialects(DialectRegistry &registry) const override {
-    registry.insert<AffineDialect>();
-    registry.insert<linalg::LinalgDialect>();
-    registry.insert<scf::SCFDialect>();
-  }
-
   Option<bool> useLinalgOps{
       *this, "use-linalg-copy",
       llvm::cl::desc("Split using a unmasked vector.transfer + linalg.fill + "
diff --git a/mlir/test/mlir-opt/commandline.mlir b/mlir/test/mlir-opt/commandline.mlir
index 4cf6ea9..f99a68d 100644
--- a/mlir/test/mlir-opt/commandline.mlir
+++ b/mlir/test/mlir-opt/commandline.mlir
@@ -1,5 +1,5 @@
 // RUN: mlir-opt --show-dialects | FileCheck %s
-// CHECK: Available Dialects:
+// CHECK: Registered Dialects:
 // CHECK: affine
 // CHECK: gpu
 // CHECK: linalg
diff --git a/mlir/tools/mlir-linalg-ods-gen/mlir-linalg-ods-gen.cpp b/mlir/tools/mlir-linalg-ods-gen/mlir-linalg-ods-gen.cpp
index 92efef6..12e6aee 100644
--- a/mlir/tools/mlir-linalg-ods-gen/mlir-linalg-ods-gen.cpp
+++ b/mlir/tools/mlir-linalg-ods-gen/mlir-linalg-ods-gen.cpp
@@ -1703,7 +1703,7 @@ int main(int argc, char **argv) {
   if (testEmitIncludeTdHeader)
     output->os() << "include \"mlir/Dialect/Linalg/IR/LinalgStructuredOps.td\"";
 
-  MLIRContext context(/*loadAllDialects=*/false);
+  MLIRContext context;
   llvm::SourceMgr mgr;
   mgr.AddNewSourceBuffer(std::move(file), llvm::SMLoc());
   Parser parser(mgr, &context);
diff --git a/mlir/tools/mlir-opt/mlir-opt.cpp b/mlir/tools/mlir-opt/mlir-opt.cpp
index 53ea4da..efcb328 100644
--- a/mlir/tools/mlir-opt/mlir-opt.cpp
+++ b/mlir/tools/mlir-opt/mlir-opt.cpp
@@ -175,10 +175,11 @@ int main(int argc, char **argv) {
   cl::ParseCommandLineOptions(argc, argv, "MLIR modular optimizer driver\n");
 
   if(showDialects) {
-    MLIRContext context(false);
-    registerAllDialects(&context);
-    llvm::outs() << "Available Dialects:\n";
-    interleave(context.getAvailableDialects(), llvm::outs(), "\n");
+    llvm::outs() << "Registered Dialects:\n";
+    MLIRContext context;
+    for(Dialect *dialect : context.getRegisteredDialects()) {
+      llvm::outs() << dialect->getNamespace() << "\n";
+    }
     return 0;
   }
 
diff --git a/mlir/tools/mlir-tblgen/DialectGen.cpp b/mlir/tools/mlir-tblgen/DialectGen.cpp
index 797ecd7..13421c4 100644
--- a/mlir/tools/mlir-tblgen/DialectGen.cpp
+++ b/mlir/tools/mlir-tblgen/DialectGen.cpp
@@ -61,14 +61,11 @@ filterForDialect(ArrayRef<llvm::Record *> records, Dialect &dialect) {
 ///
 /// {0}: The name of the dialect class.
 /// {1}: The dialect namespace.
-/// {2}: initialization code that is emitted in the ctor body before calling
-/// initialize()
 static const char *const dialectDeclBeginStr = R"(
 class {0} : public ::mlir::Dialect {
   explicit {0}(::mlir::MLIRContext *context)
     : ::mlir::Dialect(getDialectNamespace(), context,
       ::mlir::TypeID::get<{0}>()) {{
-    {2}
     initialize();
   }
   void initialize();
@@ -77,12 +74,6 @@ public:
   static ::llvm::StringRef getDialectNamespace() { return "{1}"; }
 )";
 
-/// Registration for a single dependent dialect: to be inserted in the ctor
-/// above for each dependent dialect.
-const char *const dialectRegistrationTemplate = R"(
-    getContext()->getOrLoadDialect<{0}>();
-)";
-
 /// The code block for the attribute parser/printer hooks.
 static const char *const attrParserDecl = R"(
   /// Parse an attribute registered to this dialect.
@@ -145,18 +136,9 @@ static void emitDialectDecl(Dialect &dialect,
                             iterator_range<DialectFilterIterator> dialectAttrs,
                             iterator_range<DialectFilterIterator> dialectTypes,
                             raw_ostream &os) {
-  /// Build the list of dependent dialects
-  std::string dependentDialectRegistrations;
-  {
-    llvm::raw_string_ostream dialects_os(dependentDialectRegistrations);
-    for (StringRef dependentDialect : dialect.getDependentDialects())
-      dialects_os << llvm::formatv(dialectRegistrationTemplate,
-                                   dependentDialect);
-  }
   // Emit the start of the decl.
   std::string cppName = dialect.getCppClassName();
-  os << llvm::formatv(dialectDeclBeginStr, cppName, dialect.getName(),
-                      dependentDialectRegistrations);
+  os << llvm::formatv(dialectDeclBeginStr, cppName, dialect.getName());
 
   // Check for any attributes/types registered to this dialect.  If there are,
   // add the hooks for parsing/printing.
diff --git a/mlir/tools/mlir-tblgen/PassGen.cpp b/mlir/tools/mlir-tblgen/PassGen.cpp
index b6f5f3f..c2dcdb8 100644
--- a/mlir/tools/mlir-tblgen/PassGen.cpp
+++ b/mlir/tools/mlir-tblgen/PassGen.cpp
@@ -36,7 +36,6 @@ static llvm::cl::opt<std::string>
 /// {0}: The def name of the pass record.
 /// {1}: The base class for the pass.
 /// {2): The command line argument for the pass.
-/// {3}: The dependent dialects registration.
 const char *const passDeclBegin = R"(
 //===----------------------------------------------------------------------===//
 // {0}
@@ -64,20 +63,9 @@ public:
     return std::make_unique<DerivedT>(*static_cast<const DerivedT *>(this));
   }
 
-  /// Return the dialect that must be loaded in the context before this pass.
-  void getDependentDialects(::mlir::DialectRegistry &registry) const override {
-    {3}
-  }
-
 protected:
 )";
 
-/// Registration for a single dependent dialect, to be inserted for each
-/// dependent dialect in the `getDependentDialects` above.
-const char *const dialectRegistrationTemplate = R"(
-  registry.insert<{0}>();
-)";
-
 /// Emit the declarations for each of the pass options.
 static void emitPassOptionDecls(const Pass &pass, raw_ostream &os) {
   for (const PassOption &opt : pass.getOptions()) {
@@ -106,15 +94,8 @@ static void emitPassStatisticDecls(const Pass &pass, raw_ostream &os) {
 
 static void emitPassDecl(const Pass &pass, raw_ostream &os) {
   StringRef defName = pass.getDef()->getName();
-  std::string dependentDialectRegistrations;
-  {
-    llvm::raw_string_ostream dialects_os(dependentDialectRegistrations);
-    for (StringRef dependentDialect : pass.getDependentDialects())
-      dialects_os << llvm::formatv(dialectRegistrationTemplate,
-                                   dependentDialect);
-  }
   os << llvm::formatv(passDeclBegin, defName, pass.getBaseClass(),
-                      pass.getArgument(), dependentDialectRegistrations);
+                      pass.getArgument());
   emitPassOptionDecls(pass, os);
   emitPassStatisticDecls(pass, os);
   os << "};\n";
diff --git a/mlir/tools/mlir-translate/mlir-translate.cpp b/mlir/tools/mlir-translate/mlir-translate.cpp
index 0d67286..914bd34 100644
--- a/mlir/tools/mlir-translate/mlir-translate.cpp
+++ b/mlir/tools/mlir-translate/mlir-translate.cpp
@@ -88,8 +88,7 @@ int main(int argc, char **argv) {
   // Processes the memory buffer with a new MLIRContext.
   auto processBuffer = [&](std::unique_ptr<llvm::MemoryBuffer> ownedBuffer,
                            raw_ostream &os) {
-    MLIRContext context(false);
-    registerAllDialects(&context);
+    MLIRContext context;
     context.allowUnregisteredDialects();
     context.printOpOnDiagnostic(!verifyDiagnostics);
     llvm::SourceMgr sourceMgr;
diff --git a/mlir/unittests/Dialect/Quant/QuantizationUtilsTest.cpp b/mlir/unittests/Dialect/Quant/QuantizationUtilsTest.cpp
index bae95e1..97c94a5 100644
--- a/mlir/unittests/Dialect/Quant/QuantizationUtilsTest.cpp
+++ b/mlir/unittests/Dialect/Quant/QuantizationUtilsTest.cpp
@@ -17,6 +17,9 @@
 using namespace mlir;
 using namespace mlir::quant;
 
+// Load the quant dialect
+static DialectRegistration<QuantizationDialect> QuantOpsRegistration;
+
 namespace {
 
 // Test UniformQuantizedValueConverter converts all APFloat to a magic number 5.
@@ -75,8 +78,7 @@ UniformQuantizedType getTestQuantizedType(Type storageType, MLIRContext *ctx) {
 }
 
 TEST(QuantizationUtilsTest, convertFloatAttrUniform) {
-  MLIRContext ctx(/*loadAllDialects=*/false);
-  ctx.getOrLoadDialect<QuantizationDialect>();
+  MLIRContext ctx;
   IntegerType convertedType = IntegerType::get(8, &ctx);
   auto quantizedType = getTestQuantizedType(convertedType, &ctx);
   TestUniformQuantizedValueConverter converter(quantizedType);
@@ -93,8 +95,7 @@ TEST(QuantizationUtilsTest, convertFloatAttrUniform) {
 }
 
 TEST(QuantizationUtilsTest, convertRankedDenseAttrUniform) {
-  MLIRContext ctx(/*loadAllDialects=*/false);
-  ctx.getOrLoadDialect<QuantizationDialect>();
+  MLIRContext ctx;
   IntegerType convertedType = IntegerType::get(8, &ctx);
   auto quantizedType = getTestQuantizedType(convertedType, &ctx);
   TestUniformQuantizedValueConverter converter(quantizedType);
@@ -118,8 +119,7 @@ TEST(QuantizationUtilsTest, convertRankedDenseAttrUniform) {
 }
 
 TEST(QuantizationUtilsTest, convertRankedSplatAttrUniform) {
-  MLIRContext ctx(/*loadAllDialects=*/false);
-  ctx.getOrLoadDialect<QuantizationDialect>();
+  MLIRContext ctx;
   IntegerType convertedType = IntegerType::get(8, &ctx);
   auto quantizedType = getTestQuantizedType(convertedType, &ctx);
   TestUniformQuantizedValueConverter converter(quantizedType);
@@ -143,8 +143,7 @@ TEST(QuantizationUtilsTest, convertRankedSplatAttrUniform) {
 }
 
 TEST(QuantizationUtilsTest, convertRankedSparseAttrUniform) {
-  MLIRContext ctx(/*loadAllDialects=*/false);
-  ctx.getOrLoadDialect<QuantizationDialect>();
+  MLIRContext ctx;
   IntegerType convertedType = IntegerType::get(8, &ctx);
   auto quantizedType = getTestQuantizedType(convertedType, &ctx);
   TestUniformQuantizedValueConverter converter(quantizedType);
diff --git a/mlir/unittests/Dialect/SPIRV/DeserializationTest.cpp b/mlir/unittests/Dialect/SPIRV/DeserializationTest.cpp
index 4aa2ffe..fe5632d 100644
--- a/mlir/unittests/Dialect/SPIRV/DeserializationTest.cpp
+++ b/mlir/unittests/Dialect/SPIRV/DeserializationTest.cpp
@@ -38,8 +38,7 @@ using ::testing::StrEq;
 /// diagnostic checking utilities.
 class DeserializationTest : public ::testing::Test {
 protected:
-  DeserializationTest() : context(/*loadAllDialects=*/false) {
-    context.getOrLoadDialect<mlir::spirv::SPIRVDialect>();
+  DeserializationTest() {
     // Register a diagnostic handler to capture the diagnostic so that we can
     // check it later.
     context.getDiagEngine().registerHandler([&](Diagnostic &diag) {
diff --git a/mlir/unittests/Dialect/SPIRV/SerializationTest.cpp b/mlir/unittests/Dialect/SPIRV/SerializationTest.cpp
index cb89cd6..3d57e55 100644
--- a/mlir/unittests/Dialect/SPIRV/SerializationTest.cpp
+++ b/mlir/unittests/Dialect/SPIRV/SerializationTest.cpp
@@ -36,10 +36,7 @@ using namespace mlir;
 
 class SerializationTest : public ::testing::Test {
 protected:
-  SerializationTest() : context(/*loadAllDialects=*/false) {
-    context.getOrLoadDialect<mlir::spirv::SPIRVDialect>();
-    createModuleOp();
-  }
+  SerializationTest() { createModuleOp(); }
 
   void createModuleOp() {
     OpBuilder builder(&context);
diff --git a/mlir/unittests/IR/AttributeTest.cpp b/mlir/unittests/IR/AttributeTest.cpp
index 78f7dd5..df449a0 100644
--- a/mlir/unittests/IR/AttributeTest.cpp
+++ b/mlir/unittests/IR/AttributeTest.cpp
@@ -32,7 +32,7 @@ static void testSplat(Type eltType, const EltTy &splatElt) {
 
 namespace {
 TEST(DenseSplatTest, BoolSplat) {
-  MLIRContext context(false);
+  MLIRContext context;
   IntegerType boolTy = IntegerType::get(1, &context);
   RankedTensorType shape = RankedTensorType::get({2, 2}, boolTy);
 
@@ -57,7 +57,7 @@ TEST(DenseSplatTest, BoolSplat) {
 TEST(DenseSplatTest, LargeBoolSplat) {
   constexpr int64_t boolCount = 56;
 
-  MLIRContext context(false);
+  MLIRContext context;
   IntegerType boolTy = IntegerType::get(1, &context);
   RankedTensorType shape = RankedTensorType::get({boolCount}, boolTy);
 
@@ -80,7 +80,7 @@ TEST(DenseSplatTest, LargeBoolSplat) {
 }
 
 TEST(DenseSplatTest, BoolNonSplat) {
-  MLIRContext context(false);
+  MLIRContext context;
   IntegerType boolTy = IntegerType::get(1, &context);
   RankedTensorType shape = RankedTensorType::get({6}, boolTy);
 
@@ -92,7 +92,7 @@ TEST(DenseSplatTest, BoolNonSplat) {
 
 TEST(DenseSplatTest, OddIntSplat) {
   // Test detecting a splat with an odd(non 8-bit) integer bitwidth.
-  MLIRContext context(false);
+  MLIRContext context;
   constexpr size_t intWidth = 19;
   IntegerType intTy = IntegerType::get(intWidth, &context);
   APInt value(intWidth, 10);
@@ -101,7 +101,7 @@ TEST(DenseSplatTest, OddIntSplat) {
 }
 
 TEST(DenseSplatTest, Int32Splat) {
-  MLIRContext context(false);
+  MLIRContext context;
   IntegerType intTy = IntegerType::get(32, &context);
   int value = 64;
 
@@ -109,7 +109,7 @@ TEST(DenseSplatTest, Int32Splat) {
 }
 
 TEST(DenseSplatTest, IntAttrSplat) {
-  MLIRContext context(false);
+  MLIRContext context;
   IntegerType intTy = IntegerType::get(85, &context);
   Attribute value = IntegerAttr::get(intTy, 109);
 
@@ -117,7 +117,7 @@ TEST(DenseSplatTest, IntAttrSplat) {
 }
 
 TEST(DenseSplatTest, F32Splat) {
-  MLIRContext context(false);
+  MLIRContext context;
   FloatType floatTy = FloatType::getF32(&context);
   float value = 10.0;
 
@@ -125,7 +125,7 @@ TEST(DenseSplatTest, F32Splat) {
 }
 
 TEST(DenseSplatTest, F64Splat) {
-  MLIRContext context(false);
+  MLIRContext context;
   FloatType floatTy = FloatType::getF64(&context);
   double value = 10.0;
 
@@ -133,7 +133,7 @@ TEST(DenseSplatTest, F64Splat) {
 }
 
 TEST(DenseSplatTest, FloatAttrSplat) {
-  MLIRContext context(false);
+  MLIRContext context;
   FloatType floatTy = FloatType::getF32(&context);
   Attribute value = FloatAttr::get(floatTy, 10.0);
 
@@ -141,7 +141,7 @@ TEST(DenseSplatTest, FloatAttrSplat) {
 }
 
 TEST(DenseSplatTest, BF16Splat) {
-  MLIRContext context(false);
+  MLIRContext context;
   FloatType floatTy = FloatType::getBF16(&context);
   Attribute value = FloatAttr::get(floatTy, 10.0);
 
@@ -149,7 +149,7 @@ TEST(DenseSplatTest, BF16Splat) {
 }
 
 TEST(DenseSplatTest, StringSplat) {
-  MLIRContext context(false);
+  MLIRContext context;
   Type stringType =
       OpaqueType::get(Identifier::get("test", &context), "string", &context);
   StringRef value = "test-string";
@@ -157,7 +157,7 @@ TEST(DenseSplatTest, StringSplat) {
 }
 
 TEST(DenseSplatTest, StringAttrSplat) {
-  MLIRContext context(false);
+  MLIRContext context;
   Type stringType =
       OpaqueType::get(Identifier::get("test", &context), "string", &context);
   Attribute stringAttr = StringAttr::get("test-string", stringType);
@@ -165,28 +165,28 @@ TEST(DenseSplatTest, StringAttrSplat) {
 }
 
 TEST(DenseComplexTest, ComplexFloatSplat) {
-  MLIRContext context(false);
+  MLIRContext context;
   ComplexType complexType = ComplexType::get(FloatType::getF32(&context));
   std::complex<float> value(10.0, 15.0);
   testSplat(complexType, value);
 }
 
 TEST(DenseComplexTest, ComplexIntSplat) {
-  MLIRContext context(false);
+  MLIRContext context;
   ComplexType complexType = ComplexType::get(IntegerType::get(64, &context));
   std::complex<int64_t> value(10, 15);
   testSplat(complexType, value);
 }
 
 TEST(DenseComplexTest, ComplexAPFloatSplat) {
-  MLIRContext context(false);
+  MLIRContext context;
   ComplexType complexType = ComplexType::get(FloatType::getF32(&context));
   std::complex<APFloat> value(APFloat(10.0f), APFloat(15.0f));
   testSplat(complexType, value);
 }
 
 TEST(DenseComplexTest, ComplexAPIntSplat) {
-  MLIRContext context(false);
+  MLIRContext context;
   ComplexType complexType = ComplexType::get(IntegerType::get(64, &context));
   std::complex<APInt> value(APInt(64, 10), APInt(64, 15));
   testSplat(complexType, value);
diff --git a/mlir/unittests/IR/DialectTest.cpp b/mlir/unittests/IR/DialectTest.cpp
index c43fb77..bc389ce 100644
--- a/mlir/unittests/IR/DialectTest.cpp
+++ b/mlir/unittests/IR/DialectTest.cpp
@@ -26,12 +26,12 @@ struct AnotherTestDialect : public Dialect {
 };
 
 TEST(DialectDeathTest, MultipleDialectsWithSameNamespace) {
-  MLIRContext context(false);
+  MLIRContext context;
 
   // Registering a dialect with the same namespace twice should result in a
   // failure.
-  context.getOrLoadDialect<TestDialect>();
-  ASSERT_DEATH(context.getOrLoadDialect<AnotherTestDialect>(), "");
+  context.getOrCreateDialect<TestDialect>();
+  ASSERT_DEATH(context.getOrCreateDialect<AnotherTestDialect>(), "");
 }
 
 } // end namespace
diff --git a/mlir/unittests/IR/OperationSupportTest.cpp b/mlir/unittests/IR/OperationSupportTest.cpp
index 9669330..95ddccc 100644
--- a/mlir/unittests/IR/OperationSupportTest.cpp
+++ b/mlir/unittests/IR/OperationSupportTest.cpp
@@ -25,7 +25,7 @@ static Operation *createOp(MLIRContext *context,
 
 namespace {
 TEST(OperandStorageTest, NonResizable) {
-  MLIRContext context(false);
+  MLIRContext context;
   Builder builder(&context);
 
   Operation *useOp =
@@ -49,7 +49,7 @@ TEST(OperandStorageTest, NonResizable) {
 }
 
 TEST(OperandStorageTest, Resizable) {
-  MLIRContext context(false);
+  MLIRContext context;
   Builder builder(&context);
 
   Operation *useOp =
@@ -77,7 +77,7 @@ TEST(OperandStorageTest, Resizable) {
 }
 
 TEST(OperandStorageTest, RangeReplace) {
-  MLIRContext context(false);
+  MLIRContext context;
   Builder builder(&context);
 
   Operation *useOp =
@@ -113,7 +113,7 @@ TEST(OperandStorageTest, RangeReplace) {
 }
 
 TEST(OperandStorageTest, MutableRange) {
-  MLIRContext context(false);
+  MLIRContext context;
   Builder builder(&context);
 
   Operation *useOp =
diff --git a/mlir/unittests/Pass/AnalysisManagerTest.cpp b/mlir/unittests/Pass/AnalysisManagerTest.cpp
index 958cf43..a99df39 100644
--- a/mlir/unittests/Pass/AnalysisManagerTest.cpp
+++ b/mlir/unittests/Pass/AnalysisManagerTest.cpp
@@ -24,7 +24,7 @@ struct OtherAnalysis {
 };
 
 TEST(AnalysisManagerTest, FineGrainModuleAnalysisPreservation) {
-  MLIRContext context(false);
+  MLIRContext context;
 
   // Test fine grain invalidation of the module analysis manager.
   OwningModuleRef module(ModuleOp::create(UnknownLoc::get(&context)));
@@ -45,7 +45,7 @@ TEST(AnalysisManagerTest, FineGrainModuleAnalysisPreservation) {
 }
 
 TEST(AnalysisManagerTest, FineGrainFunctionAnalysisPreservation) {
-  MLIRContext context(false);
+  MLIRContext context;
   Builder builder(&context);
 
   // Create a function and a module.
@@ -74,7 +74,7 @@ TEST(AnalysisManagerTest, FineGrainFunctionAnalysisPreservation) {
 }
 
 TEST(AnalysisManagerTest, FineGrainChildFunctionAnalysisPreservation) {
-  MLIRContext context(false);
+  MLIRContext context;
   Builder builder(&context);
 
   // Create a function and a module.
@@ -117,7 +117,7 @@ struct CustomInvalidatingAnalysis {
 };
 
 TEST(AnalysisManagerTest, CustomInvalidation) {
-  MLIRContext context(false);
+  MLIRContext context;
   Builder builder(&context);
 
   // Create a function and a module.
diff --git a/mlir/unittests/SDBM/SDBMTest.cpp b/mlir/unittests/SDBM/SDBMTest.cpp
index bbe87e3..61d6706 100644
--- a/mlir/unittests/SDBM/SDBMTest.cpp
+++ b/mlir/unittests/SDBM/SDBMTest.cpp
@@ -17,17 +17,18 @@
 
 using namespace mlir;
 
+/// Load the SDBM dialect.
+static DialectRegistration<SDBMDialect> SDBMRegistration;
 
 static MLIRContext *ctx() {
-  static thread_local MLIRContext context(false);
-  context.getOrLoadDialect<SDBMDialect>();
+  static thread_local MLIRContext context;
   return &context;
 }
 
 static SDBMDialect *dialect() {
   static thread_local SDBMDialect *d = nullptr;
   if (!d) {
-    d = ctx()->getOrLoadDialect<SDBMDialect>();
+    d = ctx()->getRegisteredDialect<SDBMDialect>();
   }
   return d;
 }
diff --git a/mlir/unittests/TableGen/OpBuildGen.cpp b/mlir/unittests/TableGen/OpBuildGen.cpp
index 46a37da..3e3256e 100644
--- a/mlir/unittests/TableGen/OpBuildGen.cpp
+++ b/mlir/unittests/TableGen/OpBuildGen.cpp
@@ -25,16 +25,11 @@ namespace mlir {
 // Test Fixture
 //===----------------------------------------------------------------------===//
 
-static MLIRContext &getContext() {
-  static MLIRContext ctx(false);
-  ctx.getOrLoadDialect<TestDialect>();
-  return ctx;
-}
 /// Test fixture for providing basic utilities for testing.
 class OpBuildGenTest : public ::testing::Test {
 protected:
   OpBuildGenTest()
-      : ctx(getContext()), builder(&ctx), loc(builder.getUnknownLoc()),
+      : ctx{}, builder(&ctx), loc(builder.getUnknownLoc()),
         i32Ty(builder.getI32Type()), f32Ty(builder.getF32Type()),
         cstI32(builder.create<TableGenConstant>(loc, i32Ty)),
         cstF32(builder.create<TableGenConstant>(loc, f32Ty)),
@@ -91,7 +86,7 @@ protected:
   }
 
 protected:
-  MLIRContext &ctx;
+  MLIRContext ctx;
   OpBuilder builder;
   Location loc;
   Type i32Ty;
diff --git a/mlir/unittests/TableGen/StructsGenTest.cpp b/mlir/unittests/TableGen/StructsGenTest.cpp
index 14b0abc..c58fedb 100644
--- a/mlir/unittests/TableGen/StructsGenTest.cpp
+++ b/mlir/unittests/TableGen/StructsGenTest.cpp
@@ -42,7 +42,7 @@ static test::TestStruct getTestStruct(mlir::MLIRContext *context) {
 /// Validates that test::TestStruct::classof correctly identifies a valid
 /// test::TestStruct.
 TEST(StructsGenTest, ClassofTrue) {
-  mlir::MLIRContext context(false);
+  mlir::MLIRContext context;
   auto structAttr = getTestStruct(&context);
   ASSERT_TRUE(test::TestStruct::classof(structAttr));
 }